public async Task UpdateTag()
{
var tag = _fixture.Create <Tag>();
var dto = new Dto.Tag(tag);
_photosService.Setup(m => m.SaveTag(It.IsAny <Tag>()))
.ReturnsAsync(tag);
var response = await _tagsController.UpdateTag(dto);
_photosService.Verify(m => m.SaveTag(It.IsAny <Tag>()),
Times.Once);
Assert.IsType <OkObjectResult>(response);
var value = ((OkObjectResult)response).Value;
Assert.IsType <Dto.Tag>(value);
var dto2 = value as Dto.Tag;
Assert.Equal(dto.TagName, dto2.TagName);
Assert.Equal(dto.TagId, dto2.TagId);
}