Calling same method on different objects in ruby

gistfile1.rb

#
# This is the base class
# for the classes below.
# Each class calls :register which
# saves its self into subclasses
#
# When the display method is called on
# the base class it loops through the collection
# insdie @@subclasses and if the instance method
# exists on that object it will be called.
# 

class Section
  @@subclasses = { }

  def self.register name
    @@subclasses[name] = self
  end

  def self.display
    @@subclasses.map do |k,v|
      #
      #Since every class that inherits Section
      #will have a display method because Section does.
      #Passing false to instance methods will fix it for
      #us so it does not look at the display method in Section
      #
      if v.instance_methods(false).include?(:display)
        v.new.display
      end
    end
  end
end

#
# Class contains a display method
# this method will be called but
# cowboy will not be.
#
class Answer < Section
  register :answer

  def display 
    puts "I am a answer"
  end

  def cowboy
    puts "I'm a cowboy"
  end
end

#
#Class contains a display method
#this method will be called but beerme
#will not be.
#
class Question < Section
  register :question

  def display
    puts "I am a question."
  end

  def beerme
    puts "Beer me"
  end
end

#
#Class does not have a instance
#method called display. It will not
#be called.
#
class Nope < Section
  register :nope

  def aa_meeting
    puts "I need help"
  end
end

#Calling base class which
#will call all its subclasses

Section.display