All the methods of a class are by default private methods and cannot
be accessed by the application programmer. If you want to make a
method public, you can include its name in the -method section
of the class declaration. In our TixArrowButton example, we
have declared that the methods flash, invert and
invoke are public methods and they can be accessed by the
application programmer. All other methods of the TixArrowButton
class will be private.