Role::Tiny is a Perl module to do minimalist role composition. Role composition
 can be thought of as much more clever and meaningful multiple inheritance.
 .
 The basics of this implementation of roles is:
  * If a method is already defined on a class, that method will not be composed
    in from the role.
  * If a method that the role "requires" to be implemented is not implemented,
    role application will fail loudly.
 .
 Unlike Class::C3, where the last class inherited from "wins," role composition
 is the other way around, where first wins. In a more complete system (see
 Moose) roles are checked to see if they clash. The goal of this is to be much
 simpler, hence disallowing composition of multiple roles at once.