text: # -*- coding:utf-8 -*-
  from twisted.internet.defer import Deferred
  from twisted.python.failure import Failure
  
  
  def got_poem(res):
      print "Your poem is served:"
      print res
  
  
  def poem_failed(err):
      print "No poetry for you."
  
  
  d = Deferred()
  
  # add a callback/errback pair to the chain
  d.addCallbacks(got_poem, poem_failed)
  
  # fire the chain with an error result
  d.errback(Failure(Exception("I have failed.")))
  
  print "Finished"
  