public async Task AttachmentDelete()
{
var mock = new Mock<ITimelineService>();
mock.Setup(m => m.FileExists(It.IsAny<string>())).Returns(true);
mock.SetupGet(m => m.CacheFolder).Returns("cache");
Attachment attachment = new Attachment();
attachment.Id = "ID1";
await attachment.DeleteAsync(mock.Object);
mock.Verify(m => m.PutJsonAsync("TimelineEventAttachment/Delete", It.Is<object>(o => o.VerifyObject("AttachmentId", "ID1"))));
mock.Verify(m => m.FileDelete($@"cache\{attachment.Name}"));
}