Allow include_vocabulary to take >1 vocabularies

lib/mida/vocabulary.rb

@@ -47,13 +47,15 @@ def self.included_vocabularies
       @included_vocabularies ||= Set.new
     end
 
-    # Include the properties from the specified vocabulary.
+    # Include the properties from the specified <tt>vocabularies</tt>.
     # This is the correct way to inherit properties from another vocabulary,
     # rather than subclassing.
-    def self.include_vocabulary(vocabulary)
-      included_vocabularies.merge(vocabulary.included_vocabularies)
-      included_vocabularies << vocabulary
-      properties.merge!(vocabulary.properties)
+    def self.include_vocabulary(*vocabularies)
+      vocabularies.each do |vocabulary|
+        included_vocabularies.merge(vocabulary.included_vocabularies)
+        included_vocabularies << vocabulary
+        properties.merge!(vocabulary.properties)
+      end
     end
 
     # Sets the regular expression to match against the +itemtype+

spec/vocabulary_spec.rb

@@ -165,10 +165,16 @@ class Product < Mida::Vocabulary
       has_many 'addons'
     end
 
+    class Vehicle < Mida::Vocabulary
+      itemtype %r{http://example\.com.*?thing$}i
+      include_vocabulary Thing
+      has_one 'colour'
+    end
+
     class Car < Mida::Vocabulary
-      include_vocabulary Product
+      include_vocabulary Product, Vehicle
       itemtype %r{http://example\.com.*?car$}i
-      has_one 'colour', 'engine'
+      has_one 'engine'
       has_many 'stickers'
     end
   end
@@ -178,19 +184,19 @@ class Car < Mida::Vocabulary
   end
 
   it "should contain included vocabularies' properties" do
-    ['description', 'make','model'].each do
+    ['description', 'make','model', 'colour'].each do
       |prop| Car.properties[prop][:num].should == :one
     end
     Car.properties['addons'][:num].should == :many
   end
 
   it "should contain new properties" do
-    ['colour','engine'].each {|prop| Car.properties[prop][:num].should == :one}
+    Car.properties['engine'][:num].should == :one
     Car.properties['stickers'][:num].should == :many
   end
 
   it '#included_vocabularies should return the included vocabularies' do
-    [Thing, Product].each do |vocab|
+    [Thing, Product, Vehicle].each do |vocab|
       Car.included_vocabularies.should include(vocab)
     end
   end