public function getHelperCount($helperType)
    {
        if ($this->isValidKey($helperType)) {
            if (!is_null($formHelperMap = $this->getHelperMap()->get($helperType))) {
                return count($formHelperMap);
            }
            return 0;
        } else {
            throw new InvalidArgumentException('Invalid form helper type given');
        }
    }