Devise\Users\Permissions\RuleList::isInGroup PHP Method

    protected function isInGroup($groupname)
    {
        if (!$this->isLoggedIn()) {
            return false;
        }
        $groups = [];
        $userGroups = [];
        $groupnames = func_get_args();
        $user = $this->User->find($this->Auth->user()->id);
        foreach ($groupnames as $groupname) {
            $groups[] = strtolower($groupname);
        }
        foreach ($user->groups as $group) {
            $userGroups[] = strtolower($group->name);
        }
        foreach ($groups as $group) {
            if (in_array($group, $userGroups)) {
                return true;
            }
        }
        return false;
    }