Can I "retroactively" add class methods from a module (after it's already been included)?
===

In Ruby, I can do this:

    module Foo
    end
    
    class Bar
      include Foo
    end
    
    module Foo
      def do_something_instancey
        puts "I'm an instance!"
      end
    end

Then, if I instantiate a `Bar` object, I can call `do_something_instancey` on it:

    b = Bar.new
    b.do_something_instancey

However, if I do this...

    module Foo
      def self.included(base)
        def base.do_something_classy do
          puts "I'm a class!"
        end
      end
    end

My understanding is that because I included `Foo` in `Bar` *before* defining that class method, I cannot call `Bar.do_something_classy` because it never got "attached" to `Bar`.

I realize that might be slightly inaccurate/not really the right terminology. Regardless, is there a way, in the above example, to attach a class method to `Bar` from `Foo` after the module has already been included?