module Foo

  def self.included(base)
    base.class_eval do
      extend ClassMethods
      include InstanceMethods
    end
  end

  module ClassMethods
    def c
      puts 'i am class method'
      puts self
      p = self.new
      p.i
    end
  end

  module InstanceMethods
    def i
      puts ' i am instance method'
    end
  end

end

class Person
  include Foo
end

Person.c
# Person.new.i