private Node buildTransformNode() {
        List<FieldRelation> relations = new ArrayList<>();
        buildRelations("1", relations);
        buildRelations("2", relations);
        buildRelations("3", relations);
        return new TransformNode("4", "transform_node",
                Arrays.asList(new FieldInfo("id", new LongFormatInfo()),
                        new FieldInfo("name", new StringFormatInfo()),
                        new FieldInfo("age", new IntFormatInfo()),
                        new FieldInfo("salary", new FloatFormatInfo()),
                        new FieldInfo("ts", new TimestampFormatInfo())),
                relations, null, null);
    }
Test for union sql parse {@link UnionNodeRelation}
inlong-sort/sort-core/src/test/java/org/apache/inlong/sort/parser/UnionSqlParseTest.java