protected function initializeClassNames()
    {
        list($this->classNameSpace, $this->className) = GeneralUtility::trimExplode('.', $this->arguments['name']);

        if (false === in_array($this->classNameSpace, self::$acceptedClassesNameSpace)) {
            throw InvalidEntryException::invalidCssClassNamespace($this->arguments['name'], self::$acceptedClassesNameSpace);
        }
    }