old_contents: import logging
  
  logger = logging.getLogger("mutagenerate")
  logger.setLevel(logging.DEBUG)
  
  logger.addHandler(logging.NullHandler())
  
new_contents: # -*- coding: utf-8 -*-
  
  import logging
  
  logger = logging.getLogger("mutagenerate")
  logger.setLevel(logging.DEBUG)
  
  logger.addHandler(logging.NullHandler())
  
subject: Update log.py