private static FunctionParam parseTargetValue(TargetValue value, String transformName) {
        if (value == null) {
            return new ConstantParam("");
        }
        boolean isConstant = value.isConstant();
        StreamField targetField = value.getTargetField();
        String fieldType = targetField.getFieldType();
        if (isConstant) {
            FormatInfo formatInfo = FieldInfoUtils.convertFieldFormat(
                    targetField.getFieldType(), targetField.getFieldFormat());
            String constant = value.getTargetConstant();
            return formatInfo.getTypeInfo() == StringTypeInfo.INSTANCE ? new StringConstantParam(constant)
                    : new ConstantParam(constant);
        } else {
            String fieldFormat = targetField.getFieldFormat();
            String fieldName = targetField.getFieldName();
            if (FieldType.FUNCTION.name().equalsIgnoreCase(fieldType)) {
                return new CustomFunction(fieldName);
            } else {
                return new FieldInfo(fieldName, transformName,
                        FieldInfoUtils.convertFieldFormat(fieldType, fieldFormat));
            }
        }
    }
Parse filter strategy from TransformResponse and convert to the filter strategy of sort protocol

@param transformResponse The transform response that may contain filter operation
@return The filter strategy, see {@link FilterStrategy}
inlong-manager/manager-pojo/src/main/java/org/apache/inlong/manager/pojo/sort/util/FilterFunctionUtils.java