Can I add custom HTTP headers to dataProcessor?

Is it possible to add custom HTTP headers to a dataProcessor object? I’d like to add my CSRF token this way (currently adding to URL).

For example, is there an event which I can use to intercept the XmlHttpRequest object just before the request?

dp.attachEvent("someEvent", function(xhr) {
    xhr.setRequestHeader("csrf-token", "xxxxxxxxxxx");
    return true;
});

Can’t be done throug API
You can locate in dhtmlxcommon.js the next line

this.xmlDoc.setRequestHeader(“X-Requested-With”,“XMLHttpRequest”);

and after it, add the code which will set the necessary HTTP header