@Override
  protected org.apache.thrift.protocol.TField getFieldDesc(_Fields setField) {
    switch (setField) {
      case INT_VALUE:
        return INT_VALUE_FIELD_DESC;
      case LONG_VALUE:
        return LONG_VALUE_FIELD_DESC;
      case STRING_VALUE:
        return STRING_VALUE_FIELD_DESC;
      case DOUBLE_VALUE:
        return DOUBLE_VALUE_FIELD_DESC;
      case FLAG:
        return FLAG_FIELD_DESC;
      case L_STRING:
        return L_STRING_FIELD_DESC;
      case UNION_MSTRING_STRING:
        return UNION_MSTRING_STRING_FIELD_DESC;
      default:
        throw new java.lang.IllegalArgumentException("Unknown field id " + setField);
    }
  }
Find the _Fields constant that matches name, or null if its not found.
serde/src/gen/thrift/gen-javabean/org/apache/hadoop/hive/serde2/thrift/test/PropValueUnion.java