public void Projects_GetAttachments() { // Set test GetData method w/o parameters request.Setup(m => m.Get <Response <IEnumerable <Attachment> > >("projects/666/attachments", null)).Returns(new Response <IEnumerable <Attachment> > { Data = new List <Attachment> { new Attachment { Id = 999 } } }); // Test Get method var result = projectsProxy.GetAttachments(666); // Verify test Assert.IsNotNull(result); Assert.AreEqual(1, result.Data.Count()); Assert.IsTrue(result.IsSuccessful); Assert.AreEqual(999, result.Data.ElementAt(0).Id); }