code: @Override
      public <E> List<E> findAll(Class<E> entityClass, String[] columnsToSelect, Object... keys)
      {
          Object connection = getConnection();
          List results = new ArrayList();
          try
          {
              for (Object key : keys)
              {
                  Object result = fetch(entityClass, key, connection, null);
                  if (result != null)
                  {
                      results.add(result);
                  }
              }
          }
          catch (InstantiationException e)
          {
              logger.error("Error during find by key:", e);
              throw new PersistenceException(e);
          }
          catch (IllegalAccessException e)
          {
              logger.error("Error during find by key:", e);
              throw new PersistenceException(e);
          }
          return results;
      }
docs: /*
  (non-Javadoc)
  
  @see com.impetus.kundera.client.Client#findAll(java.lang.Class,
  java.lang.Object[])