Get Meteor.loginToken at client end

I’m trying to do performance testing of Meteor application using JMeter. I’m using websocket plugin of JMeter to Mimic DDP call which is nothing but JSON object. Everything was fine untill we were not evaluating user session using Meteor.loginToken generated at the server and stored in Local storage of browser. But now we don’t use userId as argument object to meteor DPP method call [apparently this is not good practice].

Now to make further call, I need this loginToken, Can any one give me idea about how to get this id in client or how does it communicates to the client. Seems like the browser gets this token once user performs login, but my DDP call to login method does not return anything apart from Meteor.userId() .

Any pointers or help would be highly appreciated.