code: func getValidIntPrefix(sc *stmtctx.StatementContext, str string) (string, error) {
  	floatPrefix, err := getValidFloatPrefix(sc, str)
  	if err != nil {
  		return floatPrefix, errors.Trace(err)
  	}
  	return floatStrToIntStr(sc, floatPrefix, str)
  }
docs: // getValidIntPrefix gets prefix of the string which can be successfully parsed as int.