def respond_to_action_responses
      if !respond_to_performed? && action_responses.any?
        respond_to do |responder|
          action_responses.each {|response| instance_exec(responder, &response) }
        end
      end
    end
def respond_to_action_responses
      if !respond_to_performed? && action_responses.any?
        respond_to do |responder|
          action_responses.each {|response| instance_exec(responder, &response) }
        end
      end
    end
if the response.content_type has not been set (if it has, then responthere are responses for the current action, then respond_to them

 we rescue the case where there were no responses, so that the default_render
 action will be performed