protected function switchServerIfNeeded($currentServer, $wantedServer, LdapOperationInterface $operation)
    {
        if ($operation instanceof AuthenticationOperation || MBString::strtolower($currentServer) == MBString::strtolower($wantedServer)) {
            return;
        }
        if ($this->connection->isBound()) {
            $this->connection->close();
        }
        $this->connection->connect(null, null, false, $wantedServer);
    }