# File lib/merb-core/rack/stream_wrapper.rb, line 11
      def each(&callback)
        if Proc === @body
          @writer = lambda { |x| callback.call(x) }
          @body.call(self)
        elsif @body.is_a?(String)
          @body.each_line(&callback)
        else
          @body.each(&callback)
        end
      end