public function detachHelper($helperName, FormHelperInterface $helper)
    {
        if ($this->isValidKey($helperName)) {
            if (is_null($formHelperType = $this->resolveHelperType($helper))) {
                throw new InvalidArgumentException('Unkown form helper instance given');
            }

            if ($this->hasHelper($formHelperType)) {
                $this->getHelperMap()->get($formHelperType)->remove($helperName);
            }
        } else {
            throw new InvalidArgumentException('Not able to detach helper because invalid helper name given');
        }
        return $this;
    }