code: public static Criteria createCriteria(EntityManager entityManager, 
        String entityName, String alias) {
      errorIfClosed(entityManager);
      return new CriteriaImpl( entityManager, entityName, alias);
    }
docs: <p>
  Creates a new {@link Criteria} query for a named entity. Sets the
  specified alias for the root entity. You may later use this alias to
  refer to the  entity in {@link Criterion}, {@link Projection} and
  {@link Order} instances.
  </p>
  
  @param entityManager {@link EntityManager} for query creation
  @param entityName name of the entity
  @return new {@link Criteria} query