@Override
  public void init(Config udfConfig, Context context) {
  }
BuildOutputRecordUdf builds a SamzaSqlRelRecord with given list of key value pairs.
Useful if you need to populate fields for a Kafka message.

For example, given args = {k1, v1, k2, v2},
it returns a SamzaSqlRelRecord with fieldNames={k1, k2} and fieldValues={v1, v2},
where v1 or v2 can be any Object, including SamzaSqlRelRecord when you want to set nested field.

Consider the below nested output schema:
{
  field1,
  field2:{
    field21,
    field22
  },
  field3:{
    field31:{
      field311,
      field312
    },
    field32
  }
};
It could be built in the select statement as:
select obj1 as field1,
       BuildSamzaSqlRelRecord("field21", obj21, "field22", obj22) as field2,
       BuildSamzaSqlRelRecord("field31", BuildSamzaSqlRelRecord("field311", obj311, "field312", obj312),
                              "field32", obj32) as field3

If no args is provided, it returns an empty SamzaSqlRelRecord (with empty field names and values list).
samza-sql/src/main/java/org/apache/samza/sql/fn/BuildOutputRecordUdf.java