code: func (bm *binaryModifier) rebuild() BinaryJSON {
  	buf := make([]byte, 0, len(bm.bj.Value)+len(bm.modifyValue.Value))
  	value, tpCode := bm.rebuildTo(buf)
  	return BinaryJSON{TypeCode: tpCode, Value: value}
  }
docs: // rebuild merges the old and the modified JSON into a new BinaryJSON