code: function (offset) {
                  if (undefined === offset) {
                      offset = this.offset;
                  }
                  var val = this.readInt32(offset, false) / 65536.0;
                  return Math.ceil(val * 100000) / 100000;
              }
docs: 读取fixed类型
  
  @param {number} offset 偏移
  @return {number} float