private function bindUsingKerberos($kerberosCredentials)
    {
        putenv('KRB5CCNAME='.$kerberosCredentials);

        $bound = $this->ldapConnection->bind(null, null, true);

        if (!$bound) {
            $message = 'Bind to Active Directory failed. AD said: '.$this->ldapConnection->getLastError();

            throw new AdldapException($message);
        }

        return true;
    }