public function signMultiSigWithdraw($reference_id, $passphrase)
    {
        $response = $this->getMultiSigWithdraw($reference_id);

        $key = $this->getKey($passphrase);

        $signature = &$key;

        foreach ($response->data->details->inputs as &$input) {
            $dataToSign = $input->data_to_sign;

            foreach ($input->signers as &$signer) {
                if ($signer->signer_public_key == $signature->getPublicKey()) {
                    $signer->signed_data = $signature->signHash($dataToSign);
                    break;
                }
            }
        }

        $this->signDTrust($response);

        $reqSigs = $this->getSigCount($reference_id);

        if ($reqSigs == 0) {
            return $this->closeMultiSigTxs($reference_id);
        }

        return $reqSigs;
    }