Mocking nested function returning Deferred in Jasmine

I'm trying to write a Jasmine test for a module that uses a jQuery ajax wrapper library named jquery.rest

This module under test:

var module = function() {

  function getData() {
    var IP = client.add('ip');
        IP.read().done(function (data) {
        console.log("done");
        return data;
    });
  }

  return {
    getData: getData
  }

}();

The client variable is declared in a different file, like so:

var client = new $.RestClient('/rest/api/');

I would like to mock the read() function so that it would return a Json payload that I define in my test. The read() method returns a $.Deferred object.

I have tried different approaches (using Jasmine spies) but without success.