public static function getSizes($noOldApple = false, $noAndroid = false, $noMs = false)
    {
        $result = array_merge(self::$_sizes, array());
        if ($noOldApple)
        {
            unset($result['apple-touch-icon-57x57.png']);
            unset($result['apple-touch-icon-60x60.png']);
            unset($result['apple-touch-icon-72x72.png']);
            unset($result['apple-touch-icon-114x114.png']);
        }
        if ($noAndroid)
        {
            unset($result['android-chrome-36x36.png']);
            unset($result['android-chrome-48x48.png']);
            unset($result['android-chrome-72x72.png']);
            unset($result['android-chrome-96x96.png']);
            unset($result['android-chrome-144x144.png']);
        }
        if ($noMs)
        {
            unset($result['mstile-70x70.png']);
            unset($result['mstile-144x144.png']);
            unset($result['mstile-150x150.png']);
            unset($result['mstile-310x310.png']);
            unset($result['mstile-310x150.png']);
        }
        return $result;
    }