new_contents: class CloningStrategy(object):
      COPY = 'copy'
      RESTART = 'restart'
      RESUME = 'resume'
  
      VALUES = {COPY, RESTART, RESUME}
  
      CHOICES = (
          (COPY, COPY),
          (RESTART, RESTART),
          (RESUME, RESUME)
      )
  
subject: Add cloning strategies