code: def format_survival_rate():
      
      arguments = docopt.docopt(
          format_survival_rate.__doc__, version='cr-rate 1.0')
      with use_db(arguments['<session-file>'], WorkDB.Mode.open) as db:
          rate = survival_rate(db)
  
      print('{:.2f}'.format(rate))
docs: cr-rate
  
      Usage: cr-rate <session-file>
  
      Calculate the survival rate of a session.