code: function (length, offset) {
  
                  if (length < 0) {
                      error.raise(10002, this.length, length);
                  }
  
                  if (undefined === offset) {
                      offset = this.offset;
                  }
  
                  var littleEndian = this.littleEndian;
                  for (var i = 0; i < length; ++i) {
                      this.view.setUint8(offset + i, 0, littleEndian);
                  }
  
                  this.offset = offset + length;
  
                  return this;
              }
docs: 写空数据
  
  @param {number} length 长度
  @param {number=} offset 起始偏移
  @return {this}