private CurrentSessionContext buildCurrentSessionContext() {
		String impl = (String) properties.get( Environment.CURRENT_SESSION_CONTEXT_CLASS );
		// for backward-compatibility
		if ( impl == null ) {
			if ( canAccessTransactionManager() ) {
				impl = "jta";
			}
			else {
				return null;
			}
		}

		if ( "jta".equals( impl ) ) {
//			if ( ! transactionFactory().compatibleWithJtaSynchronization() ) {
//				LOG.autoFlushWillNotWork();
//			}
			return new JTASessionContext( this );
		}
		else if ( "thread".equals( impl ) ) {
			return new ThreadLocalSessionContext( this );
		}
		else if ( "managed".equals( impl ) ) {
			return new ManagedSessionContext( this );
		}
		else {
			try {
				Class implClass = serviceRegistry.getService( ClassLoaderService.class ).classForName( impl );
				return (CurrentSessionContext)
						implClass.getConstructor( new Class[] { SessionFactoryImplementor.class } )
						.newInstance( this );
			}
			catch( Throwable t ) {
				LOG.unableToConstructCurrentSessionContext( impl, t );
				return null;
			}
		}
	}