code: public <E> E load(Class<E> entityClass, DatastoreKey key) {
      return fetch(entityClass, key.nativeKey());
    }
docs: Retrieves and returns the entity with the given key.
  
  @param entityClass
  the expected result type
  @param key
  the entity key
  @return the entity with the given key, or <code>null</code>, if no entity exists with the given
  key.
  @throws EntityManagerException
  if any error occurs while accessing the Datastore.