private function stripWhitespace($source)
    {
        // Verificar se token_get_all existe
        if (! function_exists('token_get_all')) {
            return $source;
        }

        $output = '';
        foreach (token_get_all($source) as $token) {
            if (is_string($token)) {
                $output .= $token;
            } elseif (in_array($token[0], [T_COMMENT, T_DOC_COMMENT])) {
                $output .= str_repeat("\n", substr_count($token[1], "\n"));
            } elseif (T_WHITESPACE === $token[0]) {
                // reduce wide spaces
                $whitespace = preg_replace('{[ \t]+}', ' ', $token[1]);
                // normalize newlines to \n
                $whitespace = preg_replace('{(?:\r\n|\r|\n)}', "\n", $whitespace);
                // trim leading spaces
                $whitespace = preg_replace('{\n +}', "\n", $whitespace);
                $output .= $whitespace;
            } else {
                $output .= $token[1];
            }
        }

        return $output;
    }