public Delegate(PostInsertIdentityPersister persister, Dialect dialect, String sequenceName) {
   super(persister);
   this.dialect = dialect;
   this.sequenceNextValFragment = dialect.getSelectSequenceNextValString(sequenceName);
   this.keyColumns = getPersister().getRootTableKeyColumnNames();
   if (keyColumns.length > 1) {
     throw new HibernateException(
         "sequence-identity generator cannot be used with with multi-column keys");
   }
 }
 @Override
 public String determineBulkInsertionIdentifierGenerationSelectFragment(Dialect dialect) {
   return dialect.getSelectSequenceNextValString(getDatabaseStructure().getName());
 }