code: function (compression) {
      if (!env.isIE8 && !window.pako && compression == true)
          alert("can't compression, please include  pako!")
      else
          this.compression = compression
  }
docs: 设置数据是否压缩，fire方法默认是false
  @memberof ServerEvent
  @param  {boolean} compression 是否压缩的参数值
  @example
  app.serverEvent().setCompression(true)