private HiveOperationType toHiveOpType(ScheduledQueryMaintenanceRequestType type) throws SemanticException {
    switch (type) {
    case CREATE:
      return HiveOperationType.CREATE_SCHEDULED_QUERY;
    case ALTER:
      return HiveOperationType.ALTER_SCHEDULED_QUERY;
    case DROP:
      return HiveOperationType.DROP_SCHEDULED_QUERY;
    default:
      throw new SemanticException("Unexpected type: " + type);
    }
  }
Composes an overlay object.

Output is a flattened view of the input objects.
having the value from the first one which has it defined from the overlays.
ql/src/java/org/apache/hadoop/hive/ql/parse/ScheduledQueryAnalyzer.java