old_contents: #!/usr/bin/env python
  
  from circuits import Component, Event
  
  
  class Hello(Event):
      """Hello Event"""
  
  
  class App(Component):
  
      def hello(self):
          print("Hello World!")
  
      def started(self, component):
          self.fire(Hello())
          raise SystemExit(0)
  
  App().run()
  
new_contents: #!/usr/bin/env python
  
  """circuits Hello World"""
  
  from circuits import Component, Event
  
  
  class Hello(Event):
      """Hello Event"""
  
  
  class App(Component):
  
      def hello(self):
          """Hello Event Handler"""
  
          print("Hello World!")
  
      def started(self, component):
          """Started Event Handler
  
          This is fired internally when your application starts up and can be used to
          trigger events that only occur once during startup.
          """
  
          self.fire(Hello())  # Fire Hello Event
  
          raise SystemExit(0)  # Terminate the Application
  
  App().run()
  
subject: Document and comment hello example