public function removeUser($groupName, $username)
    {
        $groupDn = $this->dn($groupName);

        $userDn = $this->adldap->user()->dn($username);

        if (is_string($groupDn) && is_string($userDn)) {
            $del = [];
            $del['member'] = $userDn;

            return $this->connection->modDelete($groupDn, $del);
        }

        return false;
    }