public boolean isSet(_Fields field) {
    if (field == null) {
      throw new java.lang.IllegalArgumentException();
    }

    switch (field) {
    case WRITE_ID:
      return isSetWriteId();
    case DATABASE:
      return isSetDatabase();
    case TABLE:
      return isSetTable();
    case FILES:
      return isSetFiles();
    case PARTITION:
      return isSetPartition();
    case TABLE_OBJ:
      return isSetTableObj();
    case PARTITION_OBJ:
      return isSetPartitionObj();
    }
    throw new java.lang.IllegalStateException();
  }
Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise
standalone-metastore/metastore-common/src/gen/thrift/gen-javabean/org/apache/hadoop/hive/metastore/api/WriteEventInfo.java