public void MoveFile_Overwrite(NewFileSystemDelegate fsFactory)
        {
            DiscFileSystem fs = fsFactory();

            DiscFileInfo fi = fs.GetFileInfo("foo.txt");

            using (Stream s = fi.Create())
            {
                s.WriteByte(1);
            }

            DiscFileInfo fi2 = fs.GetFileInfo("foo2.txt");

            using (Stream s = fi2.Create())
            {
            }

            fs.MoveFile("foo.txt", "foo2.txt", true);

            Assert.IsFalse(fi.Exists);
            Assert.IsTrue(fi2.Exists);
            Assert.AreEqual(1, fi2.Length);
        }