code: public <E> List<E> findAll(Class<E> entityClass, String[] columnsToSelect, Object... rowIds) {
          EntityMetadata entityMetadata = KunderaMetadataManager.getEntityMetadata(kunderaMetadata, entityClass);
          List<E> results = new ArrayList<E>();
          results = find(entityClass, entityMetadata.getRelationNames(),
              entityMetadata.getRelationNames() != null && !entityMetadata.getRelationNames().isEmpty(), entityMetadata,
              rowIds);
          return results.isEmpty() ? null : results;
      }
docs: Finds a {@link List} of entities from database.
  
  @param <E>
  the element type
  @param entityClass
  the entity class
  @param columnsToSelect
  TODO
  @param rowIds
  the row ids
  @return the list