title: Loopback mock session
body: <p>I'm using loopback with express session to store cartId.</p>
  
  <p>But I need to inject cartId on request session in order to make my tests work.</p>
  
  <p>So on my remote method I have</p>
  
  <pre><code>Cart.get = function (req, cb) {
      Service.getCart(req, req.session.cartId)
      .then(function (result) {
          cb(null, result);
      })
      .catch(cb);
  };
  
  Cart.remoteMethod(
      'get',
      {
          accepts: { arg: 'req', type: 'object', 'http': { source: 'req' } },
          returns: { arg: 'cart', type: 'object', root: true },
          http: { path: '/', verb: 'get' }
      }
  );
  </code></pre>
  
  <p>How can I force req.session.cartId for my tests?</p>
  
  <p>Thanks</p>