protected static function setupToken(&$context, $left = '{{', $right = '}}')
    {
        parent::setupToken($context, $left, $right);

        if (self::$compileHelpersOnly) {
            $helperTokens = array();
            foreach ($context['helpers'] as $helper => $value) {
                $helperTokens[] = $helper . '.*?';
            }
            $helperTokens = implode('|', $helperTokens);

            $context['tokens']['search'] = "/^(.*?)(\\s*)($left)(~?)([\\^#\\/!&>]?)(" . $helperTokens . ")(~?)($right)(\\s*)(.*)\$/s";
        }
    }