diff --git a/.brutal.yml b/.brutal.yml
index d2e3cf9..774eda5 100644
--- a/.brutal.yml
+++ b/.brutal.yml
@@ -1,19 +1,20 @@
 ---
 header: |
+  #!/usr/bin/env ruby
   # frozen_string_literal: false
 
-  require 'simplecov'
+  require "simplecov"
 
-  ::SimpleCov.command_name 'Brutal test suite'
+  ::SimpleCov.command_name "Brutal test suite"
   ::SimpleCov.start
 
-  require './lib/spectus'
+  require "./lib/spectus"
 
   self.class.include ::Spectus
 
 subject: |
   begin
-    it { 'foo'.%{challenge} }.%{level} %{matcher}
+    it { "foo".%{challenge} }.%{level} %{matcher}
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -22,7 +23,7 @@ contexts:
   challenge:
     - "upcase"
     - "itself"
-    - "gsub!('f', 'b')"
+    - 'gsub!("f", "b")'
     - "boom"
     - "empty?(4)"
   level:
@@ -39,7 +40,7 @@ contexts:
   matcher:
     - "raise_exception(NoMethodError)"
     - "raise_exception(ArgumentError)"
-    - "eql('foo')"
+    - 'eql("foo")'
     - "equal(42)"
 
 actuals:
diff --git a/.github/config/rubocop_linter_action.yml b/.github/config/rubocop_linter_action.yml
index 3eead5a..585ee79 100644
--- a/.github/config/rubocop_linter_action.yml
+++ b/.github/config/rubocop_linter_action.yml
@@ -1,6 +1,9 @@
 versions:
+  - rubocop-md
   - rubocop-performance
+  - rubocop-rake
   - rubocop-thread_safety
 
 rubocop_fail_level: warning
 check_scope: modified
+base_branch: origin/main
diff --git a/.github/workflows/rubocop.yml b/.github/workflows/rubocop.yml
index a9c0a3e..0ee9829 100644
--- a/.github/workflows/rubocop.yml
+++ b/.github/workflows/rubocop.yml
@@ -8,7 +8,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: RuboCop Linter Action
-      uses: andrewmcodes/rubocop-linter-action@v3.2.0
+      uses: andrewmcodes/rubocop-linter-action@v3.3.0
 
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.rubocop.yml b/.rubocop.yml
index 9830aa0..1608a23 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,14 +1,31 @@
-require:
-  - rubocop-performance
-  - rubocop-thread_safety
-
 inherit_from: .rubocop_todo.yml
 
 AllCops:
   NewCops: enable
+  TargetRubyVersion: 2.7
 
   Exclude:
     - test.rb
 
+require:
+  - rubocop-md
+  - rubocop-performance
+  - rubocop-rake
+  - rubocop-thread_safety
+
+# Enforcing double quotes reduces the times where you need to switch to Crystal.
 Style/StringLiterals:
-  EnforcedStyle: single_quotes
+  EnforcedStyle: double_quotes
+
+# We do not need to support Ruby 1.9, so this is good to use.
+Style/SymbolArray:
+  Enabled: true
+
+# Most readable form.
+Layout/HashAlignment:
+  EnforcedHashRocketStyle: table
+  EnforcedColonStyle: table
+
+# Check with yard instead.
+Style/Documentation:
+  Enabled: false
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index d096e44..9b92727 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -6,14 +6,7 @@
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
-# Offense count: 1
-# Configuration parameters: Include.
-# Include: **/*.gemspec
-Gemspec/RequiredRubyVersion:
-  Exclude:
-    - 'spectus.gemspec'
-
-# Offense count: 51
+# Offense count: 44
 # Cop supports --auto-correct.
 # Configuration parameters: AllowMultipleStyles, EnforcedHashRocketStyle, EnforcedColonStyle, EnforcedLastArgumentHashStyle.
 # SupportedHashRocketStyles: key, separator, table
@@ -24,6 +17,12 @@ Layout/HashAlignment:
     - 'lib/spectus/expectation_target.rb'
     - 'lib/spectus/requirement_level/base.rb'
 
+# Offense count: 2
+# Configuration parameters: CheckForMethodsWithNoSideEffects.
+Lint/Void:
+  Exclude:
+    - 'README.md'
+
 # Offense count: 2
 # Configuration parameters: CountComments, CountAsOne, ExcludedMethods.
 Metrics/MethodLength:
@@ -33,3 +32,14 @@ Metrics/MethodLength:
 # Configuration parameters: CountKeywordArgs.
 Metrics/ParameterLists:
   Max: 8
+
+# Offense count: 3
+Style/MixinUsage:
+  Exclude:
+    - 'README.md'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/StringConcatenation:
+  Exclude:
+    - 'README.md'
diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000..37c2961
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+2.7.2
diff --git a/.travis.yml b/.travis.yml
index 06c1528..d0b8f32 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,8 +8,8 @@ before_install:
 script:
   - bundle exec rake test
 rvm:
-  - 2.6
   - 2.7
+  - 3.0
   - ruby-head
 matrix:
   allow_failures:
diff --git a/Gemfile b/Gemfile
index 7f4f5e9..be173b2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
-source 'https://rubygems.org'
+source "https://rubygems.org"
 
 gemspec
diff --git a/Gemfile.lock b/Gemfile.lock
index 269d078..c87caf8 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,49 +1,56 @@
 PATH
   remote: .
   specs:
-    spectus (3.1.2)
+    spectus (3.1.3)
       defi (~> 2.0.4)
       matchi (~> 2.0.0)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    ast (2.4.1)
+    ast (2.4.2)
     aw (0.1.11)
     brutal (1.1.1)
     defi (2.0.4)
       aw (~> 0.1.10)
-    docile (1.3.2)
+    docile (1.3.5)
     matchi (2.0.0)
-    parallel (1.19.2)
-    parser (2.7.1.4)
+    parallel (1.20.1)
+    parser (3.0.1.1)
       ast (~> 2.4.1)
     rainbow (3.0.0)
-    rake (13.0.1)
-    regexp_parser (1.7.1)
-    rexml (3.2.4)
-    rubocop (0.90.0)
+    rake (13.0.3)
+    regexp_parser (2.1.1)
+    rexml (3.2.5)
+    rubocop (1.14.0)
       parallel (~> 1.10)
-      parser (>= 2.7.1.1)
+      parser (>= 3.0.0.0)
       rainbow (>= 2.2.2, < 4.0)
-      regexp_parser (>= 1.7)
+      regexp_parser (>= 1.8, < 3.0)
       rexml
-      rubocop-ast (>= 0.3.0, < 1.0)
+      rubocop-ast (>= 1.5.0, < 2.0)
       ruby-progressbar (~> 1.7)
-      unicode-display_width (>= 1.4.0, < 2.0)
-    rubocop-ast (0.3.0)
-      parser (>= 2.7.1.4)
-    rubocop-performance (1.8.0)
-      rubocop (>= 0.87.0)
-    rubocop-thread_safety (0.4.1)
-      rubocop (>= 0.51.0)
-    ruby-progressbar (1.10.1)
-    simplecov (0.19.0)
+      unicode-display_width (>= 1.4.0, < 3.0)
+    rubocop-ast (1.5.0)
+      parser (>= 3.0.1.1)
+    rubocop-md (1.0.1)
+      rubocop (>= 1.0)
+    rubocop-performance (1.11.3)
+      rubocop (>= 1.7.0, < 2.0)
+      rubocop-ast (>= 0.4.0)
+    rubocop-rake (0.5.1)
+      rubocop
+    rubocop-thread_safety (0.4.2)
+      rubocop (>= 0.53.0)
+    ruby-progressbar (1.11.0)
+    simplecov (0.21.2)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
-    simplecov-html (0.12.2)
-    unicode-display_width (1.7.0)
-    yard (0.9.25)
+      simplecov_json_formatter (~> 0.1)
+    simplecov-html (0.12.3)
+    simplecov_json_formatter (0.1.3)
+    unicode-display_width (2.0.0)
+    yard (0.9.26)
 
 PLATFORMS
   ruby
@@ -52,7 +59,9 @@ DEPENDENCIES
   brutal
   bundler
   rake
+  rubocop-md
   rubocop-performance
+  rubocop-rake
   rubocop-thread_safety
   simplecov
   spectus!
diff --git a/LICENSE.md b/LICENSE.md
index 3a4c8bc..ec7a293 100644
--- a/LICENSE.md
+++ b/LICENSE.md
@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2014-2020 Cyril Kato
+Copyright (c) 2014-2021 Cyril Kato
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/README.md b/README.md
index 21b4011..3a1baff 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@
 Add this line to your application's Gemfile:
 
 ```ruby
-gem 'spectus'
+gem "spectus"
 ```
 
 And then execute:
@@ -59,8 +59,8 @@ Example of test without isolation:
 
 ```ruby
 include Spectus
-greeting = 'Hello, world!'
-it { greeting.gsub!('world', 'Alice') }.MUST eql 'Hello, Alice!'
+greeting = "Hello, world!"
+it { greeting.gsub!("world", "Alice") }.MUST eql "Hello, Alice!"
 # => Spectus::Result::Pass(actual: "Hello, Alice!", error: nil, expected: "Hello, Alice!", got: true, matcher: :eql, negate: false, level: :MUST, valid: true)
 greeting # => "Hello, Alice!"
 ```
@@ -69,8 +69,8 @@ Example of test in isolation:
 
 ```ruby
 include Spectus
-greeting = 'Hello, world!'
-it { greeting.gsub!('world', 'Alice') }.MUST! eql 'Hello, Alice!'
+greeting = "Hello, world!"
+it { greeting.gsub!("world", "Alice") }.MUST! eql "Hello, Alice!"
 # => Spectus::Result::Pass(actual: "Hello, Alice!", error: nil, expected: "Hello, Alice!", got: true, matcher: :eql, negate: false, level: :MUST, valid: true)
 greeting # => "Hello, world!"
 ```
@@ -88,7 +88,7 @@ include Spectus
 Given the "`ルビー`" object, when it receives `valid_encoding?` method, then it **MUST** be `true`:
 
 ```ruby
-it { 'ルビー'.valid_encoding? }.MUST be_true
+it { "ルビー".valid_encoding? }.MUST be_true
 # => Spectus::Result::Pass(actual: true, error: nil, expected: nil, got: true, matcher: :be_true, negate: false, level: :MUST, valid: true)
 ```
 
@@ -99,7 +99,7 @@ The result of the test shows that the spec passed.
 Given the "`foo`" object, when it receives `length` method, then it **MUST NOT** raise the `NoMethodError` exception:
 
 ```ruby
-it { 'foo'.length }.MUST_NOT raise_exception NoMethodError
+it { "foo".length }.MUST_NOT raise_exception NoMethodError
 # => Spectus::Result::Pass(actual: 3, error: nil, expected: NoMethodError, got: true, matcher: :raise_exception, negate: true, level: :MUST, valid: true)
 ```
 
@@ -122,7 +122,7 @@ However, because there isn't any exception, the result of the test shows that th
 Given the "`1`" object, when it receives `+(1)` method, then it **SHOULD NOT** return the "`11`" value:
 
 ```ruby
-it { '1' + 1 }.SHOULD_NOT eql '11'
+it { "1" + 1 }.SHOULD_NOT eql "11"
 # raise Spectus::Result::Fail(actual: nil, error: #<TypeError: no implicit conversion of Integer into String>, expected: "11", got: nil, matcher: :eql, negate: true, level: :SHOULD, valid: false)
 ```
 
@@ -133,7 +133,7 @@ There was a `TypeError` exception, the result of the test shows that the spec fa
 Given the "`foo`" object, when it receives `blank?` method, then it **MAY** be `false`:
 
 ```ruby
-it { 'foo'.blank? }.MAY be_false
+it { "foo".blank? }.MAY be_false
 # => Spectus::Result::Pass(actual: nil, error: #<NoMethodError: undefined method `blank?' for "foo":String>, expected: nil, got: nil, matcher: :be_false, negate: false, level: :MAY, valid: false)
 ```
 
diff --git a/Rakefile b/Rakefile
index 5a48141..7f56e13 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,23 +1,19 @@
 # frozen_string_literal: true
 
-require 'bundler/gem_tasks'
-require 'rake/testtask'
-require 'rubocop/rake_task'
-
-RuboCop::RakeTask.new
+require "bundler/gem_tasks"
+require "rake/testtask"
+require "rubocop/rake_task"
+require "yard"
 
 Rake::TestTask.new do |t|
-  t.pattern = 'test.rb'
+  t.pattern = "test.rb"
   t.verbose = true
   t.warning = true
 end
 
-namespace :test do
-  task :coverage do
-    ENV['COVERAGE'] = 'true'
-    Rake::Task['test'].invoke
-  end
-end
+RuboCop::RakeTask.new
+YARD::Rake::YardocTask.new
+
+Dir["tasks/**/*.rake"].each { |t| load t }
 
-task(:doc_stats) { ruby '-S yard stats' }
-task default: %i[test doc_stats rubocop]
+task default: %i[yard brutal rubocop:auto_correct test]
diff --git a/VERSION.semver b/VERSION.semver
index ef538c2..ff365e0 100644
--- a/VERSION.semver
+++ b/VERSION.semver
@@ -1 +1 @@
-3.1.2
+3.1.3
diff --git a/bin/console b/bin/console
index cd7914d..25f0403 100755
--- a/bin/console
+++ b/bin/console
@@ -1,8 +1,8 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
 
-require 'bundler/setup'
-require 'spectus'
-require 'irb'
+require "bundler/setup"
+require "spectus"
+require "irb"
 
 IRB.start
diff --git a/lib/spectus.rb b/lib/spectus.rb
index 5bc5dc4..c1f509b 100644
--- a/lib/spectus.rb
+++ b/lib/spectus.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require 'matchi/helper'
+require "matchi/helper"
 
 # Namespace for the Spectus library.
 #
@@ -23,4 +23,4 @@ def it(&input)
   end
 end
 
-require_relative File.join('spectus', 'expectation_target')
+require_relative File.join("spectus", "expectation_target")
diff --git a/lib/spectus/exam.rb b/lib/spectus/exam.rb
index 7e0e6d7..55ddaa3 100644
--- a/lib/spectus/exam.rb
+++ b/lib/spectus/exam.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require 'defi'
+require "defi"
 
 module Spectus
   # This class evaluate the expectation with the passed block.
diff --git a/lib/spectus/expectation_target.rb b/lib/spectus/expectation_target.rb
index a5e6fb3..9b0b316 100644
--- a/lib/spectus/expectation_target.rb
+++ b/lib/spectus/expectation_target.rb
@@ -193,6 +193,6 @@ def MAY!(matcher)
   end
 end
 
-require_relative File.join('requirement_level', 'must')
-require_relative File.join('requirement_level', 'should')
-require_relative File.join('requirement_level', 'may')
+require_relative File.join("requirement_level", "must")
+require_relative File.join("requirement_level", "should")
+require_relative File.join("requirement_level", "may")
diff --git a/lib/spectus/requirement_level/base.rb b/lib/spectus/requirement_level/base.rb
index e5db847..52d54a3 100644
--- a/lib/spectus/requirement_level/base.rb
+++ b/lib/spectus/requirement_level/base.rb
@@ -65,7 +65,7 @@ def details
 
       # @return [Symbol] The requirement level.
       def level
-        self.class.name.split('::').fetch(-1).upcase.to_sym
+        self.class.name.split("::").fetch(-1).upcase.to_sym
       end
 
       # @note The boolean comparison between the actual value and the expected
@@ -79,6 +79,6 @@ def negate?
   end
 end
 
-require_relative File.join('..', 'exam')
-require_relative File.join('..', 'result', 'fail')
-require_relative File.join('..', 'result', 'pass')
+require_relative File.join("..", "exam")
+require_relative File.join("..", "result", "fail")
+require_relative File.join("..", "result", "pass")
diff --git a/lib/spectus/requirement_level/may.rb b/lib/spectus/requirement_level/may.rb
index db7c89c..1acad3b 100644
--- a/lib/spectus/requirement_level/may.rb
+++ b/lib/spectus/requirement_level/may.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require_relative 'must'
+require_relative "must"
 
 module Spectus
   module RequirementLevel
diff --git a/lib/spectus/requirement_level/must.rb b/lib/spectus/requirement_level/must.rb
index 67b698b..fa046cf 100644
--- a/lib/spectus/requirement_level/must.rb
+++ b/lib/spectus/requirement_level/must.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require_relative 'base'
+require_relative "base"
 
 module Spectus
   module RequirementLevel
diff --git a/lib/spectus/requirement_level/should.rb b/lib/spectus/requirement_level/should.rb
index c1c5d10..9e4b4d4 100644
--- a/lib/spectus/requirement_level/should.rb
+++ b/lib/spectus/requirement_level/should.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require_relative 'must'
+require_relative "must"
 
 module Spectus
   module RequirementLevel
diff --git a/lib/spectus/result/common.rb b/lib/spectus/result/common.rb
index fe63257..9905804 100644
--- a/lib/spectus/result/common.rb
+++ b/lib/spectus/result/common.rb
@@ -97,14 +97,14 @@ def inspect
       #
       # @return [String] A readable string of the definition.
       def definition
-        [matcher, expected&.inspect].compact.join(' ')
+        [matcher, expected&.inspect].compact.join(" ")
       end
 
       # The negation, if any.
       #
       # @return [String] The negation, or an empty string.
       def maybe_negate
-        negate? ? ' not' : ''
+        negate? ? " not" : ""
       end
 
       # The summary of the result.
diff --git a/lib/spectus/result/fail.rb b/lib/spectus/result/fail.rb
index 93931f2..ecc7290 100644
--- a/lib/spectus/result/fail.rb
+++ b/lib/spectus/result/fail.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require_relative 'common'
+require_relative "common"
 
 module Spectus
   module Result
@@ -55,9 +55,9 @@ def to_sym
       # @return [String] The char that identify the result.
       def char
         if failure?
-          'F'
+          "F"
         else
-          'E'
+          "E"
         end
       end
 
@@ -66,9 +66,9 @@ def char
       # @return [String] The emoji that identify the result.
       def emoji
         if failure?
-          '❌'
+          "❌"
         else
-          '💥'
+          "💥"
         end
       end
     end
diff --git a/lib/spectus/result/pass.rb b/lib/spectus/result/pass.rb
index ac28408..ecd1f35 100644
--- a/lib/spectus/result/pass.rb
+++ b/lib/spectus/result/pass.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require_relative 'common'
+require_relative "common"
 
 module Spectus
   module Result
@@ -60,11 +60,11 @@ def to_sym
       # @return [String] The char that identify the result.
       def char
         if success?
-          '.'
+          "."
         elsif warning?
-          'W'
+          "W"
         else
-          'I'
+          "I"
         end
       end
 
@@ -73,11 +73,11 @@ def char
       # @return [String] The emoji that identify the result.
       def emoji
         if success?
-          '✅'
+          "✅"
         elsif warning?
-          '⚠️'
+          "⚠️"
         else
-          '💡'
+          "💡"
         end
       end
     end
diff --git a/spectus.gemspec b/spectus.gemspec
index 7a19136..bbcd9f4 100644
--- a/spectus.gemspec
+++ b/spectus.gemspec
@@ -1,26 +1,27 @@
 # frozen_string_literal: true
 
 Gem::Specification.new do |spec|
-  spec.name         = 'spectus'
-  spec.version      = File.read('VERSION.semver').chomp
-  spec.author       = 'Cyril Kato'
-  spec.email        = 'contact@cyril.email'
+  spec.name         = "spectus"
+  spec.version      = File.read("VERSION.semver").chomp
+  spec.author       = "Cyril Kato"
+  spec.email        = "contact@cyril.email"
   spec.summary      = "Expectation library with RFC 2119's requirement levels 🚥"
   spec.description  = spec.summary
-  spec.homepage     = 'https://github.com/fixrb/spectus'
-  spec.license      = 'MIT'
-  spec.files        = Dir['LICENSE.md', 'README.md', 'lib/**/*']
+  spec.homepage     = "https://github.com/fixrb/spectus"
+  spec.required_ruby_version = Gem::Requirement.new(">= 2.7.0")
+  spec.license      = "MIT"
+  spec.files        = Dir["LICENSE.md", "README.md", "lib/**/*"]
 
-  spec.required_ruby_version = '>= 2.3.0'
+  spec.add_dependency "defi",   "~> 2.0.4"
+  spec.add_dependency "matchi", "~> 2.0.0"
 
-  spec.add_dependency 'defi',   '~> 2.0.4'
-  spec.add_dependency 'matchi', '~> 2.0.0'
-
-  spec.add_development_dependency 'brutal'
-  spec.add_development_dependency 'bundler'
-  spec.add_development_dependency 'rake'
-  spec.add_development_dependency 'rubocop-performance'
-  spec.add_development_dependency 'rubocop-thread_safety'
-  spec.add_development_dependency 'simplecov'
-  spec.add_development_dependency 'yard'
+  spec.add_development_dependency "brutal"
+  spec.add_development_dependency "bundler"
+  spec.add_development_dependency "rake"
+  spec.add_development_dependency "rubocop-md"
+  spec.add_development_dependency "rubocop-performance"
+  spec.add_development_dependency "rubocop-rake"
+  spec.add_development_dependency "rubocop-thread_safety"
+  spec.add_development_dependency "simplecov"
+  spec.add_development_dependency "yard"
 end
diff --git a/tasks/brutal.rake b/tasks/brutal.rake
new file mode 100644
index 0000000..12b73c7
--- /dev/null
+++ b/tasks/brutal.rake
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+desc "Generate the picture of the behavior of the code"
+task :brutal do
+  sh("bundle exec brutal")
+  sh("chmod +x test.rb")
+end
diff --git a/test.rb b/test.rb
old mode 100644
new mode 100755
index 6b5cbd4..f30236e
--- a/test.rb
+++ b/test.rb
@@ -1,11 +1,12 @@
+#!/usr/bin/env ruby
 # frozen_string_literal: false
 
-require 'simplecov'
+require "simplecov"
 
-::SimpleCov.command_name 'Brutal test suite'
+::SimpleCov.command_name "Brutal test suite"
 ::SimpleCov.start
 
-require './lib/spectus'
+require "./lib/spectus"
 
 self.class.include ::Spectus
 
@@ -13,7 +14,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST raise_exception(NoMethodError)
+    it { "foo".upcase }.MUST raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -45,7 +46,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST raise_exception(ArgumentError)
+    it { "foo".upcase }.MUST raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -77,7 +78,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST eql('foo')
+    it { "foo".upcase }.MUST eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -109,7 +110,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST equal(42)
+    it { "foo".upcase }.MUST equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -141,7 +142,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD raise_exception(NoMethodError)
+    it { "foo".upcase }.SHOULD raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -173,7 +174,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD raise_exception(ArgumentError)
+    it { "foo".upcase }.SHOULD raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -205,7 +206,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD eql('foo')
+    it { "foo".upcase }.SHOULD eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -237,7 +238,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD equal(42)
+    it { "foo".upcase }.SHOULD equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -269,7 +270,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MAY raise_exception(NoMethodError)
+    it { "foo".upcase }.MAY raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -301,7 +302,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MAY raise_exception(ArgumentError)
+    it { "foo".upcase }.MAY raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -333,7 +334,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MAY eql('foo')
+    it { "foo".upcase }.MAY eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -365,7 +366,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MAY equal(42)
+    it { "foo".upcase }.MAY equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -397,7 +398,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST_NOT raise_exception(NoMethodError)
+    it { "foo".upcase }.MUST_NOT raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -429,7 +430,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST_NOT raise_exception(ArgumentError)
+    it { "foo".upcase }.MUST_NOT raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -461,7 +462,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST_NOT eql('foo')
+    it { "foo".upcase }.MUST_NOT eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -493,7 +494,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST_NOT equal(42)
+    it { "foo".upcase }.MUST_NOT equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -525,7 +526,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD_NOT raise_exception(NoMethodError)
+    it { "foo".upcase }.SHOULD_NOT raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -557,7 +558,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD_NOT raise_exception(ArgumentError)
+    it { "foo".upcase }.SHOULD_NOT raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -589,7 +590,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD_NOT eql('foo')
+    it { "foo".upcase }.SHOULD_NOT eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -621,7 +622,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD_NOT equal(42)
+    it { "foo".upcase }.SHOULD_NOT equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -653,7 +654,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST! raise_exception(NoMethodError)
+    it { "foo".upcase }.MUST! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -685,7 +686,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST! raise_exception(ArgumentError)
+    it { "foo".upcase }.MUST! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -717,7 +718,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST! eql('foo')
+    it { "foo".upcase }.MUST! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -749,7 +750,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST! equal(42)
+    it { "foo".upcase }.MUST! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -781,7 +782,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD! raise_exception(NoMethodError)
+    it { "foo".upcase }.SHOULD! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -813,7 +814,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD! raise_exception(ArgumentError)
+    it { "foo".upcase }.SHOULD! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -845,7 +846,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD! eql('foo')
+    it { "foo".upcase }.SHOULD! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -877,7 +878,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD! equal(42)
+    it { "foo".upcase }.SHOULD! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -909,7 +910,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MAY! raise_exception(NoMethodError)
+    it { "foo".upcase }.MAY! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -941,7 +942,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MAY! raise_exception(ArgumentError)
+    it { "foo".upcase }.MAY! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -973,7 +974,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MAY! eql('foo')
+    it { "foo".upcase }.MAY! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1005,7 +1006,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MAY! equal(42)
+    it { "foo".upcase }.MAY! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1037,7 +1038,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST_NOT! raise_exception(NoMethodError)
+    it { "foo".upcase }.MUST_NOT! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1069,7 +1070,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST_NOT! raise_exception(ArgumentError)
+    it { "foo".upcase }.MUST_NOT! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1101,7 +1102,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST_NOT! eql('foo')
+    it { "foo".upcase }.MUST_NOT! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1133,7 +1134,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.MUST_NOT! equal(42)
+    it { "foo".upcase }.MUST_NOT! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1165,7 +1166,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD_NOT! raise_exception(NoMethodError)
+    it { "foo".upcase }.SHOULD_NOT! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1197,7 +1198,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD_NOT! raise_exception(ArgumentError)
+    it { "foo".upcase }.SHOULD_NOT! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1229,7 +1230,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD_NOT! eql('foo')
+    it { "foo".upcase }.SHOULD_NOT! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1261,7 +1262,7 @@
 
 actual = begin
   begin
-    it { 'foo'.upcase }.SHOULD_NOT! equal(42)
+    it { "foo".upcase }.SHOULD_NOT! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1293,7 +1294,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST raise_exception(NoMethodError)
+    it { "foo".itself }.MUST raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1325,7 +1326,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST raise_exception(ArgumentError)
+    it { "foo".itself }.MUST raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1357,7 +1358,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST eql('foo')
+    it { "foo".itself }.MUST eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1389,7 +1390,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST equal(42)
+    it { "foo".itself }.MUST equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1421,7 +1422,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD raise_exception(NoMethodError)
+    it { "foo".itself }.SHOULD raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1453,7 +1454,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD raise_exception(ArgumentError)
+    it { "foo".itself }.SHOULD raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1485,7 +1486,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD eql('foo')
+    it { "foo".itself }.SHOULD eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1517,7 +1518,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD equal(42)
+    it { "foo".itself }.SHOULD equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1549,7 +1550,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MAY raise_exception(NoMethodError)
+    it { "foo".itself }.MAY raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1581,7 +1582,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MAY raise_exception(ArgumentError)
+    it { "foo".itself }.MAY raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1613,7 +1614,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MAY eql('foo')
+    it { "foo".itself }.MAY eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1645,7 +1646,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MAY equal(42)
+    it { "foo".itself }.MAY equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1677,7 +1678,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST_NOT raise_exception(NoMethodError)
+    it { "foo".itself }.MUST_NOT raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1709,7 +1710,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST_NOT raise_exception(ArgumentError)
+    it { "foo".itself }.MUST_NOT raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1741,7 +1742,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST_NOT eql('foo')
+    it { "foo".itself }.MUST_NOT eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1773,7 +1774,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST_NOT equal(42)
+    it { "foo".itself }.MUST_NOT equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1805,7 +1806,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD_NOT raise_exception(NoMethodError)
+    it { "foo".itself }.SHOULD_NOT raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1837,7 +1838,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD_NOT raise_exception(ArgumentError)
+    it { "foo".itself }.SHOULD_NOT raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1869,7 +1870,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD_NOT eql('foo')
+    it { "foo".itself }.SHOULD_NOT eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1901,7 +1902,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD_NOT equal(42)
+    it { "foo".itself }.SHOULD_NOT equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1933,7 +1934,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST! raise_exception(NoMethodError)
+    it { "foo".itself }.MUST! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1965,7 +1966,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST! raise_exception(ArgumentError)
+    it { "foo".itself }.MUST! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -1997,7 +1998,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST! eql('foo')
+    it { "foo".itself }.MUST! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2029,7 +2030,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST! equal(42)
+    it { "foo".itself }.MUST! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2061,7 +2062,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD! raise_exception(NoMethodError)
+    it { "foo".itself }.SHOULD! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2093,7 +2094,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD! raise_exception(ArgumentError)
+    it { "foo".itself }.SHOULD! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2125,7 +2126,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD! eql('foo')
+    it { "foo".itself }.SHOULD! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2157,7 +2158,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD! equal(42)
+    it { "foo".itself }.SHOULD! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2189,7 +2190,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MAY! raise_exception(NoMethodError)
+    it { "foo".itself }.MAY! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2221,7 +2222,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MAY! raise_exception(ArgumentError)
+    it { "foo".itself }.MAY! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2253,7 +2254,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MAY! eql('foo')
+    it { "foo".itself }.MAY! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2285,7 +2286,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MAY! equal(42)
+    it { "foo".itself }.MAY! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2317,7 +2318,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST_NOT! raise_exception(NoMethodError)
+    it { "foo".itself }.MUST_NOT! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2349,7 +2350,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST_NOT! raise_exception(ArgumentError)
+    it { "foo".itself }.MUST_NOT! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2381,7 +2382,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST_NOT! eql('foo')
+    it { "foo".itself }.MUST_NOT! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2413,7 +2414,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.MUST_NOT! equal(42)
+    it { "foo".itself }.MUST_NOT! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2445,7 +2446,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD_NOT! raise_exception(NoMethodError)
+    it { "foo".itself }.SHOULD_NOT! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2477,7 +2478,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD_NOT! raise_exception(ArgumentError)
+    it { "foo".itself }.SHOULD_NOT! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2509,7 +2510,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD_NOT! eql('foo')
+    it { "foo".itself }.SHOULD_NOT! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2541,7 +2542,7 @@
 
 actual = begin
   begin
-    it { 'foo'.itself }.SHOULD_NOT! equal(42)
+    it { "foo".itself }.SHOULD_NOT! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2573,7 +2574,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST raise_exception(NoMethodError)
+    it { "foo".gsub!("f", "b") }.MUST raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2605,7 +2606,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST raise_exception(ArgumentError)
+    it { "foo".gsub!("f", "b") }.MUST raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2637,7 +2638,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST eql('foo')
+    it { "foo".gsub!("f", "b") }.MUST eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2669,7 +2670,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST equal(42)
+    it { "foo".gsub!("f", "b") }.MUST equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2701,7 +2702,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD raise_exception(NoMethodError)
+    it { "foo".gsub!("f", "b") }.SHOULD raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2733,7 +2734,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD raise_exception(ArgumentError)
+    it { "foo".gsub!("f", "b") }.SHOULD raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2765,7 +2766,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD eql('foo')
+    it { "foo".gsub!("f", "b") }.SHOULD eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2797,7 +2798,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD equal(42)
+    it { "foo".gsub!("f", "b") }.SHOULD equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2829,7 +2830,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MAY raise_exception(NoMethodError)
+    it { "foo".gsub!("f", "b") }.MAY raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2861,7 +2862,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MAY raise_exception(ArgumentError)
+    it { "foo".gsub!("f", "b") }.MAY raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2893,7 +2894,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MAY eql('foo')
+    it { "foo".gsub!("f", "b") }.MAY eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2925,7 +2926,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MAY equal(42)
+    it { "foo".gsub!("f", "b") }.MAY equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2957,7 +2958,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST_NOT raise_exception(NoMethodError)
+    it { "foo".gsub!("f", "b") }.MUST_NOT raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -2989,7 +2990,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST_NOT raise_exception(ArgumentError)
+    it { "foo".gsub!("f", "b") }.MUST_NOT raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3021,7 +3022,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST_NOT eql('foo')
+    it { "foo".gsub!("f", "b") }.MUST_NOT eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3053,7 +3054,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST_NOT equal(42)
+    it { "foo".gsub!("f", "b") }.MUST_NOT equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3085,7 +3086,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD_NOT raise_exception(NoMethodError)
+    it { "foo".gsub!("f", "b") }.SHOULD_NOT raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3117,7 +3118,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD_NOT raise_exception(ArgumentError)
+    it { "foo".gsub!("f", "b") }.SHOULD_NOT raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3149,7 +3150,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD_NOT eql('foo')
+    it { "foo".gsub!("f", "b") }.SHOULD_NOT eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3181,7 +3182,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD_NOT equal(42)
+    it { "foo".gsub!("f", "b") }.SHOULD_NOT equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3213,7 +3214,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST! raise_exception(NoMethodError)
+    it { "foo".gsub!("f", "b") }.MUST! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3245,7 +3246,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST! raise_exception(ArgumentError)
+    it { "foo".gsub!("f", "b") }.MUST! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3277,7 +3278,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST! eql('foo')
+    it { "foo".gsub!("f", "b") }.MUST! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3309,7 +3310,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST! equal(42)
+    it { "foo".gsub!("f", "b") }.MUST! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3341,7 +3342,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD! raise_exception(NoMethodError)
+    it { "foo".gsub!("f", "b") }.SHOULD! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3373,7 +3374,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD! raise_exception(ArgumentError)
+    it { "foo".gsub!("f", "b") }.SHOULD! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3405,7 +3406,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD! eql('foo')
+    it { "foo".gsub!("f", "b") }.SHOULD! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3437,7 +3438,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD! equal(42)
+    it { "foo".gsub!("f", "b") }.SHOULD! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3469,7 +3470,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MAY! raise_exception(NoMethodError)
+    it { "foo".gsub!("f", "b") }.MAY! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3501,7 +3502,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MAY! raise_exception(ArgumentError)
+    it { "foo".gsub!("f", "b") }.MAY! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3533,7 +3534,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MAY! eql('foo')
+    it { "foo".gsub!("f", "b") }.MAY! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3565,7 +3566,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MAY! equal(42)
+    it { "foo".gsub!("f", "b") }.MAY! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3597,7 +3598,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST_NOT! raise_exception(NoMethodError)
+    it { "foo".gsub!("f", "b") }.MUST_NOT! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3629,7 +3630,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST_NOT! raise_exception(ArgumentError)
+    it { "foo".gsub!("f", "b") }.MUST_NOT! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3661,7 +3662,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST_NOT! eql('foo')
+    it { "foo".gsub!("f", "b") }.MUST_NOT! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3693,7 +3694,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.MUST_NOT! equal(42)
+    it { "foo".gsub!("f", "b") }.MUST_NOT! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3725,7 +3726,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD_NOT! raise_exception(NoMethodError)
+    it { "foo".gsub!("f", "b") }.SHOULD_NOT! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3757,7 +3758,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD_NOT! raise_exception(ArgumentError)
+    it { "foo".gsub!("f", "b") }.SHOULD_NOT! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3789,7 +3790,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD_NOT! eql('foo')
+    it { "foo".gsub!("f", "b") }.SHOULD_NOT! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3821,7 +3822,7 @@
 
 actual = begin
   begin
-    it { 'foo'.gsub!('f', 'b') }.SHOULD_NOT! equal(42)
+    it { "foo".gsub!("f", "b") }.SHOULD_NOT! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3853,7 +3854,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST raise_exception(NoMethodError)
+    it { "foo".boom }.MUST raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3885,7 +3886,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST raise_exception(ArgumentError)
+    it { "foo".boom }.MUST raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3917,7 +3918,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST eql('foo')
+    it { "foo".boom }.MUST eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3949,7 +3950,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST equal(42)
+    it { "foo".boom }.MUST equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -3981,7 +3982,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD raise_exception(NoMethodError)
+    it { "foo".boom }.SHOULD raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4013,7 +4014,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD raise_exception(ArgumentError)
+    it { "foo".boom }.SHOULD raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4045,7 +4046,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD eql('foo')
+    it { "foo".boom }.SHOULD eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4077,7 +4078,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD equal(42)
+    it { "foo".boom }.SHOULD equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4109,7 +4110,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MAY raise_exception(NoMethodError)
+    it { "foo".boom }.MAY raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4141,7 +4142,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MAY raise_exception(ArgumentError)
+    it { "foo".boom }.MAY raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4173,7 +4174,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MAY eql('foo')
+    it { "foo".boom }.MAY eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4205,7 +4206,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MAY equal(42)
+    it { "foo".boom }.MAY equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4237,7 +4238,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST_NOT raise_exception(NoMethodError)
+    it { "foo".boom }.MUST_NOT raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4269,7 +4270,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST_NOT raise_exception(ArgumentError)
+    it { "foo".boom }.MUST_NOT raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4301,7 +4302,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST_NOT eql('foo')
+    it { "foo".boom }.MUST_NOT eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4333,7 +4334,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST_NOT equal(42)
+    it { "foo".boom }.MUST_NOT equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4365,7 +4366,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD_NOT raise_exception(NoMethodError)
+    it { "foo".boom }.SHOULD_NOT raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4397,7 +4398,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD_NOT raise_exception(ArgumentError)
+    it { "foo".boom }.SHOULD_NOT raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4429,7 +4430,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD_NOT eql('foo')
+    it { "foo".boom }.SHOULD_NOT eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4461,7 +4462,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD_NOT equal(42)
+    it { "foo".boom }.SHOULD_NOT equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4493,7 +4494,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST! raise_exception(NoMethodError)
+    it { "foo".boom }.MUST! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4525,7 +4526,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST! raise_exception(ArgumentError)
+    it { "foo".boom }.MUST! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4557,7 +4558,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST! eql('foo')
+    it { "foo".boom }.MUST! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4589,7 +4590,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST! equal(42)
+    it { "foo".boom }.MUST! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4621,7 +4622,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD! raise_exception(NoMethodError)
+    it { "foo".boom }.SHOULD! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4653,7 +4654,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD! raise_exception(ArgumentError)
+    it { "foo".boom }.SHOULD! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4685,7 +4686,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD! eql('foo')
+    it { "foo".boom }.SHOULD! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4717,7 +4718,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD! equal(42)
+    it { "foo".boom }.SHOULD! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4749,7 +4750,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MAY! raise_exception(NoMethodError)
+    it { "foo".boom }.MAY! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4781,7 +4782,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MAY! raise_exception(ArgumentError)
+    it { "foo".boom }.MAY! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4813,7 +4814,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MAY! eql('foo')
+    it { "foo".boom }.MAY! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4845,7 +4846,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MAY! equal(42)
+    it { "foo".boom }.MAY! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4877,7 +4878,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST_NOT! raise_exception(NoMethodError)
+    it { "foo".boom }.MUST_NOT! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4909,7 +4910,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST_NOT! raise_exception(ArgumentError)
+    it { "foo".boom }.MUST_NOT! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4941,7 +4942,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST_NOT! eql('foo')
+    it { "foo".boom }.MUST_NOT! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -4973,7 +4974,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.MUST_NOT! equal(42)
+    it { "foo".boom }.MUST_NOT! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5005,7 +5006,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD_NOT! raise_exception(NoMethodError)
+    it { "foo".boom }.SHOULD_NOT! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5037,7 +5038,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD_NOT! raise_exception(ArgumentError)
+    it { "foo".boom }.SHOULD_NOT! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5069,7 +5070,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD_NOT! eql('foo')
+    it { "foo".boom }.SHOULD_NOT! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5101,7 +5102,7 @@
 
 actual = begin
   begin
-    it { 'foo'.boom }.SHOULD_NOT! equal(42)
+    it { "foo".boom }.SHOULD_NOT! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5133,7 +5134,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST raise_exception(NoMethodError)
+    it { "foo".empty?(4) }.MUST raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5165,7 +5166,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST raise_exception(ArgumentError)
+    it { "foo".empty?(4) }.MUST raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5197,7 +5198,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST eql('foo')
+    it { "foo".empty?(4) }.MUST eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5229,7 +5230,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST equal(42)
+    it { "foo".empty?(4) }.MUST equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5261,7 +5262,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD raise_exception(NoMethodError)
+    it { "foo".empty?(4) }.SHOULD raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5293,7 +5294,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD raise_exception(ArgumentError)
+    it { "foo".empty?(4) }.SHOULD raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5325,7 +5326,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD eql('foo')
+    it { "foo".empty?(4) }.SHOULD eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5357,7 +5358,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD equal(42)
+    it { "foo".empty?(4) }.SHOULD equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5389,7 +5390,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MAY raise_exception(NoMethodError)
+    it { "foo".empty?(4) }.MAY raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5421,7 +5422,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MAY raise_exception(ArgumentError)
+    it { "foo".empty?(4) }.MAY raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5453,7 +5454,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MAY eql('foo')
+    it { "foo".empty?(4) }.MAY eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5485,7 +5486,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MAY equal(42)
+    it { "foo".empty?(4) }.MAY equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5517,7 +5518,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST_NOT raise_exception(NoMethodError)
+    it { "foo".empty?(4) }.MUST_NOT raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5549,7 +5550,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST_NOT raise_exception(ArgumentError)
+    it { "foo".empty?(4) }.MUST_NOT raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5581,7 +5582,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST_NOT eql('foo')
+    it { "foo".empty?(4) }.MUST_NOT eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5613,7 +5614,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST_NOT equal(42)
+    it { "foo".empty?(4) }.MUST_NOT equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5645,7 +5646,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD_NOT raise_exception(NoMethodError)
+    it { "foo".empty?(4) }.SHOULD_NOT raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5677,7 +5678,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD_NOT raise_exception(ArgumentError)
+    it { "foo".empty?(4) }.SHOULD_NOT raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5709,7 +5710,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD_NOT eql('foo')
+    it { "foo".empty?(4) }.SHOULD_NOT eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5741,7 +5742,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD_NOT equal(42)
+    it { "foo".empty?(4) }.SHOULD_NOT equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5773,7 +5774,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST! raise_exception(NoMethodError)
+    it { "foo".empty?(4) }.MUST! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5805,7 +5806,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST! raise_exception(ArgumentError)
+    it { "foo".empty?(4) }.MUST! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5837,7 +5838,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST! eql('foo')
+    it { "foo".empty?(4) }.MUST! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5869,7 +5870,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST! equal(42)
+    it { "foo".empty?(4) }.MUST! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5901,7 +5902,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD! raise_exception(NoMethodError)
+    it { "foo".empty?(4) }.SHOULD! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5933,7 +5934,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD! raise_exception(ArgumentError)
+    it { "foo".empty?(4) }.SHOULD! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5965,7 +5966,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD! eql('foo')
+    it { "foo".empty?(4) }.SHOULD! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -5997,7 +5998,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD! equal(42)
+    it { "foo".empty?(4) }.SHOULD! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6029,7 +6030,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MAY! raise_exception(NoMethodError)
+    it { "foo".empty?(4) }.MAY! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6061,7 +6062,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MAY! raise_exception(ArgumentError)
+    it { "foo".empty?(4) }.MAY! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6093,7 +6094,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MAY! eql('foo')
+    it { "foo".empty?(4) }.MAY! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6125,7 +6126,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MAY! equal(42)
+    it { "foo".empty?(4) }.MAY! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6157,7 +6158,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST_NOT! raise_exception(NoMethodError)
+    it { "foo".empty?(4) }.MUST_NOT! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6189,7 +6190,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST_NOT! raise_exception(ArgumentError)
+    it { "foo".empty?(4) }.MUST_NOT! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6221,7 +6222,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST_NOT! eql('foo')
+    it { "foo".empty?(4) }.MUST_NOT! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6253,7 +6254,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.MUST_NOT! equal(42)
+    it { "foo".empty?(4) }.MUST_NOT! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6285,7 +6286,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD_NOT! raise_exception(NoMethodError)
+    it { "foo".empty?(4) }.SHOULD_NOT! raise_exception(NoMethodError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6317,7 +6318,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD_NOT! raise_exception(ArgumentError)
+    it { "foo".empty?(4) }.SHOULD_NOT! raise_exception(ArgumentError)
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6349,7 +6350,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD_NOT! eql('foo')
+    it { "foo".empty?(4) }.SHOULD_NOT! eql("foo")
   rescue ::Spectus::Result::Fail => e
     e
   end
@@ -6381,7 +6382,7 @@
 
 actual = begin
   begin
-    it { 'foo'.empty?(4) }.SHOULD_NOT! equal(42)
+    it { "foo".empty?(4) }.SHOULD_NOT! equal(42)
   rescue ::Spectus::Result::Fail => e
     e
   end