One of the most powerful things about Moose is that with roles and easy
"anonymous" class creation we are blessed with a fantastic new way of
creating classes, often on the fly, out of other classes and those
composable bits of behaviour, roles.

Even better, this application of discrete chunks of behaviours enables
people simply using a class to extend and tweak its behaviour in new
ways -- possibly ways never contemplated by the authors of the classes
being altered.