    # File lib/action_controller/response.rb, line 150
        def each(&callback)
          if @body.respond_to?(:call)
            @writer = lambda { |x| callback.call(x) }
            @body.call(self, self)
          elsif @body.respond_to?(:to_str)
            yield @body
          else
            @body.each(&callback)
          end

          @writer = callback
          @block.call(self) if @block
        end