default Optional<ColumnEntity> singleResult(ColumnQuery query) throws NonUniqueResultException, NullPointerException {
  List<ColumnEntity> entities=find(query);
  if (entities.isEmpty()) {
    return Optional.empty();
  }
  if (entities.size() == 1) {
    return Optional.of(entities.get(0));
  }
  throw new NonUniqueResultException("The query returns more than one entity, query: " + query);
}

default Optional < ColumnEntity > singleResult ( ColumnQuery query ) throws NonUniqueResultException , NullPointerException { List < ColumnEntity > entities = find ( query ) ; if ( entities . isEmpty ( ) ) { return Optional . empty ( ) ; } if ( entities . size ( ) == 1 ) { return Optional . of ( entities . get ( 0 ) ) ; } throw new NonUniqueResultException ( "The query returns more than one entity, query: " + query ) ; }
returns a single entity from query
