require 'set'
require 'test/unit'

class Mock
  def initialize(class_to_mock=nil)
    @class_to_mock = class_to_mock
    @expectations = Set.new
  end
  
  def expects(message)
    @expectations.add(message)
  end
  
  def verify
    
  end
  
  def method_missing(method, *args)
    if (not @expectations.include? method)
      raise "Unexpected extra call to #{method}"
    end
  end
  
end