Add docs to CircuitBreakerMiddleware::should_suppress?

lib/exceptional_middleware/middleware/circuit_breaker_middleware.rb

@@ -4,6 +4,17 @@ def self.included(includer)
   end
 
   module ClassMethods
+    # Method indicating whether the circuit breaker has been tripped and whether
+    # or not the successor should be called. Must be implemeneted by including
+    # Class/Module.
+    #
+    # @param remote_exception [RemotelyExceptional::RemoteException] The remote
+    #   exception that needs handling.
+    # @raise [NotImplementedError] Raised if the incluing Class or Module does
+    # not implement it's own should_suppress? method.
+    # @return [Boolean] A Boolean value indicating whether or not the successor
+    #   should be called. When true, the successor method will not be invoked.
+    #   When false, the successor will be invoked.
     def should_suppress?(remote_exception)
       raise NotImplementedError, "#{__method__} must be implemented by including class!"
     end