gistfile1.rb

module BeerDrinkerRole
  def drink
  end
end

class BeerDrinker
  include BeerDrinkerRole
end

module AnotherRole
  def another_method
  end
end

class Another
 include AnotherRole
end

# and we can now
BeerDrinker.new.extend(AnotherRole)
Another.new.extend(BeerDrinkerRole) # etc.