code: func (bj BinaryJSON) GetString() []byte {
  	strLen, lenLen := uint64(bj.Value[0]), 1
  	if strLen >= utf8.RuneSelf {
  		strLen, lenLen = binary.Uvarint(bj.Value)
  	}
  	return bj.Value[lenLen : lenLen+int(strLen)]
  }
docs: // GetString gets the string value.