# File lib/em/protocols/memcache.rb, line 78
      def set key, val, exptime = 0, &cb
        callback{
          val = val.to_s
          send_cmd :set, key, 0, exptime, val.respond_to?(:bytesize) ? val.bytesize : val.size, !block_given?
          send_data val
          send_data Cdelimiter
          @set_cbs << cb if cb
        }
      end