mixin.rb

module InstanceModule
  def track
    "Tracking todo: #{self.name}" 
  end
end
 
module ClassModule
 
  def class_name
    "Tracking class: #{self.name}"
  end
end
 
class Todo
  include InstanceModule
  extend ClassModule
 
  attr_reader :name
 
  def initialize(task_name)
    @name = task_name
  end
end
 
t = Todo.new('read a blog')
puts t.track
puts Todo.class_name