public void ProgressFileDownloader_Cleanup_AssertFilesDeleted()
{
//------------Setup for test--------------------------
var dir = new Mock<IDirectory>();
dir.Setup(a => a.GetFiles("c:\bob")).Returns(new[] { "tmpa", "tmpb", "tmpc" });
var file = new Mock<IFile>();
ProgressFileDownloader.PerformCleanup(dir.Object,"c:\bob",file.Object);
file.Verify(a=>a.Delete(It.IsAny<string>()),Times.Exactly(3));
}