public void ShouldCopyFile()
        {
            var a = Path.GetTempFileName();
            var b = Path.GetTempFileName();

            File.Delete(b);

            const string expected = "blubb";

            File.WriteAllText(a, expected);
            _sut.CopyFile(a, b);
            Assert.True(File.Exists(a));
            Assert.True(File.Exists(b));

            var actual = File.ReadAllText(b);

            Assert.AreEqual(expected, actual);
        }