old_contents: from disco.job import Job
  from disco.worker.classic.func import chain_reader
  
  class FirstJob(Job):
      input = ['raw://0', 'raw://0']
  
      @staticmethod
      def map(line, params):
          yield int(line) + 1, ""
  
  class ChainJob(Job):
      map_reader = staticmethod(chain_reader)
  
      @staticmethod
      def map(key_value, params):
          yield int(key_value[0]) + 1, value
  
  if __name__ == "__main__":
      last = FirstJob().run()
      for i in xrange(9):
          last = ChainJob().run(input=last.wait())
      print(last.name)
  
new_contents: from disco.job import Job
  from disco.worker.classic.func import chain_reader
  
  class FirstJob(Job):
      input = ['raw://0', 'raw://0']
  
      @staticmethod
      def map(line, params):
          yield int(line) + 1, ""
  
  class ChainJob(Job):
      map_reader = staticmethod(chain_reader)
  
      @staticmethod
      def map(key_value, params):
          yield int(key_value[0]) + 1, key_value[1]
  
  if __name__ == "__main__":
      last = FirstJob().run()
      for i in xrange(9):
          last = ChainJob().run(input=last.wait())
      print(last.name)
  
subject: fix a syntax fix in example.