protected function validateData(EntityGroup $group, $groupname)
    {
        $errors = array();
        
        // Groupname
        if ($this->groupManager->hasGroupForName($groupname) && $this->groupManager->getGroupForName($groupname)->getUuid() != $group->getUuid()) {
            $errors[] = new Error(Error::GENERAL_ERROR, $this->translate('The groupname is already in use.', '\\Zepi\\Web\\AccessControl'));
        }
        
        if (count($errors) > 0) {
            return $errors;
        }
        
        return true;
    }