public static function get_instance() : Core {

		if ( null === self::$_instance ) {
			self::$_instance = new Core();
		}

		return self::$_instance;
	}
public static function get_instance() : Core {

		if ( null === self::$_instance ) {
			self::$_instance = new Core();
		}

		return self::$_instance;
	}
public static function get_instance ( ) : Core { if ( null === self :: $ _instance ) { self :: $ _instance = new Core ( ) ; } return self :: $ _instance ; }
Get Core instance.

@return Core Core instance.
Get Core instance .