Paymetric XiPay SOAP API integration using NodeJS : Authorisation issues

I am trying to do Paymetric XiPay SOAP API integration using NodeJS. For this purpose I am using node-soap package.

After creating soapClient using this package I am setting the username and password on soapClient using its BasicAuthSecurity function.

My username has following value : 'domain\name', to escape the existing '\' the username is provided as follows : 'domain\\name'.

But when I try to use the client I got error message saying:

401 - Unauthorized: Access is denied due to invalid credentials.

After close inspection of my soapClient instance figured out that, the username property in soapClient has value 'domain\\name' not 'domain\name'.

So, how can I set a user name with single '\' for soapClient.

following is the code snippet I have written for this:

var soap = require('soap');

var xipay_serviceURL  = 'https://qqq.xipaynet.com/aaa/bbb.asmx';
var xipay_user        = "paymetric\\samplename";
var xipay_password    = 'samplePassword*';
var wsdlURL = './XiPayWS3x.wsdl';

soap.createClient(wsdlURL, { endpoint: xipay_serviceURL }, function(err, client) {
    if(err){
        console.log(err);
        return false;
    }
    if(client){
        var security = new soap.BasicAuthSecurity(xipay_user, xipay_password);
        client.setSecurity(security);    
    }
});

via Kharkooza Boche