/**
	 * Return the persistent instance of the given entity class with the given identifier,
	 * assuming that the instance exists. This method might return a proxied instance that
	 * is initialized on-demand, when a non-identifier method is accessed.
	 * <br><br>
	 * You should not use this method to determine if an instance exists (use <tt>get()</tt>
	 * instead). Use this only to retrieve an instance that you assume exists, where non-existence
	 * would be an actual error.
	 *
	 * @param entityName a persistent class
	 * @param id a valid identifier of an existing persistent instance of the class
	 *
	 * @return the persistent instance or proxy
	 */
	public Object load(String entityName, Serializable id);

	/**
	 * Return the persistent instance of the given named entity with the given identifier,
	 * or null if there is no such persistent instance. (If the instance is already associated
	 * with the session, return that instance. This method never returns an uninitialized instance.)
	 *
	 * @param entityName the entity name
	 * @param id an identifier
	 *
	 * @return a persistent instance or null
	 */
	public Object get(String entityName, Serializable id);

	/**
	 * Create {@link Criteria} instance for the given class (entity or subclasses/implementors).
	 *
	 * @param persistentClass The class, which is an entity, or has entity subclasses/implementors
	 *
	 * @return The criteria instance for manipulation and execution
	 */
	public Criteria createCriteria(Class persistentClass);

	/**
	 * Create {@link Criteria} instance for the given entity name.
	 *
	 * @param entityName The entity name

	 * @return The criteria instance for manipulation and execution
	 */
	public Criteria createCriteria(String entityName);