public void TestComplement()
 {
     Assert.Equal(87654, Manipulator.Complement(12345));
     Assert.Equal(2668, Manipulator.Complement(7331));
     Assert.Equal(8, Manipulator.Complement(1));
     Assert.Equal(1999, Manipulator.Complement(8000));
     Assert.Equal(8000, Manipulator.Complement(1999));
     Assert.Equal(888888, Manipulator.Complement(111111));
 }