I have just tested with your code and the compiler is throwing an error.
"The type TestOne must implement the inherited abstract method JohnnyNumber.doSomethingElse()".
Could you please check again.
posted 8 years ago
OK, I have figured it out. I changed (and recompiled) the interface when I added the additional method. However, I did not recompile the TestOne class. (I didn't think I had too because I changed no code.) Upon recompiling, the error appears.