Ruby Plus

This is the final episode based on Why the luck stiff's "Seeing Metaclasses clearly" article.

This episode ends with an illustration of a powerful metaprogramming concept that every Ruby programmer should know. 

Prerequisite: instance_eval, changing self in Ruby episodes and previous episodes on metaclasses.

 Correction: self inside the Class << self is not the FooSub but is the metaclass of FooSub.