public void IndexerPropertyValidatesPropertyNameWithValidValue()
        {
            var viewModel = new StubViewModel
            {
                RequiredProperty = "Some Value"
            };

            Assert.IsNull(viewModel["RequiredProperty"]);
        }
        public void IndexerPropertyValidatesPropertyNameWithInvalidValue()
        {
            var viewModel = new StubViewModel();

            Assert.IsNotNull(viewModel["RequiredProperty"]);
        }
 public void IDataErrorInfo_ErrorProperty_IsNotImplemented()
 {
     var viewModel = new StubViewModel();
     var value     = viewModel.Error;
 }