docs: function(userId, applicationId, callerIPAddress) {
      return new Promise((resolve, reject) => {
        this._start()
            .uri('/api/login')
            .urlSegment(userId)
            .urlSegment(applicationId)
            .urlParameter('ipAddress', callerIPAddress)
            .put()
            .go(this._responseHandler(resolve, reject));
      });
    }