# File lib/rr/double_definitions/double_definition_create.rb, line 61
        def add_implementation_strategy(implementation_strategy_class, subject=NO_SUBJECT, method_name=nil, &definition_eval_block)
          add_strategy(subject, method_name, definition_eval_block) do
            self.implementation_strategy = implementation_strategy_class.new(self)
          end
        end