public void TimesFail()
{
var mountfs = new MountFileSystem();
Assert.Throws <FileNotFoundException>(() => mountfs.SetCreationTime("/toto.txt", DateTime.Now));
Assert.Throws <FileNotFoundException>(() => mountfs.SetLastAccessTime("/toto.txt", DateTime.Now));
Assert.Throws <FileNotFoundException>(() => mountfs.SetLastWriteTime("/toto.txt", DateTime.Now));
}
