    # File lib/active_resource/http_mock.rb, line 175
        def initialize(body, message = 200, headers = {})
          @body, @message, @headers = body, message.to_s, headers
          @code = @message[0,3].to_i

          resp_cls = Net::HTTPResponse::CODE_TO_OBJ[@code.to_s]
          if resp_cls && !resp_cls.body_permitted?
            @body = nil
          end

          if @body.nil?
            self['Content-Length'] = "0"
          else
            self['Content-Length'] = body.size.to_s
          end
        end