public static function instance($prototype = null)
    {
        if (!self::$instance || $prototype) {
            if ($prototype instanceof HTMLPurifier) {
                self::$instance = $prototype;
            } elseif ($prototype) {
                self::$instance = new HTMLPurifier($prototype);
            } else {
                self::$instance = new HTMLPurifier();
            }
        }
        return self::$instance;
    }
public static function instance($prototype = null)
    {
        if (!self::$instance || $prototype) {
            if ($prototype instanceof HTMLPurifier) {
                self::$instance = $prototype;
            } elseif ($prototype) {
                self::$instance = new HTMLPurifier($prototype);
            } else {
                self::$instance = new HTMLPurifier();
            }
        }
        return self::$instance;
    }
public static function instance ( $ prototype = null ) { if ( ! self :: $ instance || $ prototype ) { if ( $ prototype instanceof HTMLPurifier ) { self :: $ instance = $ prototype ; } elseif ( $ prototype ) { self :: $ instance = new HTMLPurifier ( $ prototype ) ; } else { self :: $ instance = new HTMLPurifier ( ) ; } } return self :: $ instance ; }
Singleton for enforcing just one HTML Purifier in your system

@param HTMLPurifier|HTMLPurifier_Config $prototype Optional prototype
HTMLPurifier instance to overload singleton with,
or HTMLPurifier_Config instance to configure the
generated version with.

@return HTMLPurifier
Singleton for enforcing just one HTML Purifier in your system