public static function instance() {
        global $CFG;
        if (is_null(self::$singletoninstance)) {
            if (!empty($CFG->perfdebug) and $CFG->perfdebug > 7) {
                self::$singletoninstance = new performance_measuring_filter_manager();
            } else {
                self::$singletoninstance = new self();
            }
        }
        return self::$singletoninstance;
    }
public static function instance() {
        global $CFG;
        if (is_null(self::$singletoninstance)) {
            if (!empty($CFG->perfdebug) and $CFG->perfdebug > 7) {
                self::$singletoninstance = new performance_measuring_filter_manager();
            } else {
                self::$singletoninstance = new self();
            }
        }
        return self::$singletoninstance;
    }
public static function instance ( ) { global $ CFG ; if ( is_null ( self :: $ singletoninstance ) ) { if ( ! empty ( $ CFG -> perfdebug ) and $ CFG -> perfdebug > 7 ) { self :: $ singletoninstance = new performance_measuring_filter_manager ( ) ; } else { self :: $ singletoninstance = new self ( ) ; } } return self :: $ singletoninstance ; }
Factory method. Use this to get the filter manager.

@return filter_manager the singleton instance.
Factory method . Use this to get the filter manager .