@Override
    public Object parse(SourceData sourceData, int rowIndex, Context context) {
        if (numberParser == null) {
            return null;
        }
        Object numberObj = numberParser.parse(sourceData, rowIndex, context);
        if (numberObj == null) {
            return null;
        }
        BigDecimal numberValue = OperatorTools.parseBigDecimal(numberObj);

        BigDecimal temp = numberValue.remainder(new BigDecimal(chrSum));
        BigDecimal res = (temp.compareTo(BigDecimal.ZERO) >= 0) ? temp : temp.add(new BigDecimal(chrSum));

        return String.valueOf((char) res.intValue());
    }
ChrFunction  ->  chr(integer)
description:
- Return NULL if 'integer' is NULL;
- Return the ASCII character having the binary equivalent to 'integer'.
inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/arithmetic/ChrFunction.java