converting to the same class while comparing (equals(Obj)) & Adding a final class

1.) Converted 'success' and 'error' to String class while comparing it with another string while applying equals(Obj).

2.) Added a final class instead of implementing a constant interface.
Have a look at http://gitready.com/advanced/2009/02/10/squashing-commits-with-rebase.html. YOu will need commandline client to do it :).