elegant_module_override.rb source: http://blog.jayfields.com/2006/12/ruby-alias-method-alternative.html

elegant_module_override.rb

class ClockRadio
  on = self.instance_method(:on!)
  
  define_method(:on!) do
    on.bind(self).call
    @display_time = true
  end
  
  def display_time?
    @display_time
  end
end