nifty_inheritance.rb

class Me
  include Parent
  
  def use_swimming_pool
    puts "This pool is so refreshing!"
  end
  
  def go_on_vacation
    expose :use_swimming_pool
  end
  
  def return_from_vacation
    conceal :use_swimming_pool
  end
end

class Neighbor
  include Adoptable
  
  def attempt_to(method)
    begin
      self.send method
    rescue
      puts "Oops, guess I can't do that"
    end
  end
end

me = Me.new
bob = Neighbor.new
me.adopt(bob)

bob.attempt_to :use_swimming_pool # Can't do it!
me.go_on_vacation
bob.attempt_to :use_swimming_pool # This works
me.return_from_vacation
bob.attempt_to :use_swimming_pool # Can't do it!