public async Task ShouldRequestAllFromTheApi()
        {
            var client = Mock.Of <ApiClient>();

            IList <RegistrationGroup> groups = new List <RegistrationGroup>()
            {
                new RegistrationGroup(), new RegistrationGroup()
            };

            Mock.Get(client).Setup(c => c.GetList <RegistrationGroup>(RegistrationGroupsResource.ResourceName, It.IsAny <ExpandoObject>())).Returns(Task.FromResult(groups));

            var resource = new RegistrationGroupsResource(client);

            await resource.All();

            Mock.Get(client).VerifyAll();
        }