old_contents: __author__ = 'z00283065'
  
  class storage():
      pass
new_contents: # -*- coding: utf-8 -*-
  """
  docker_registry.drivers.mos
  ~~~~~~~~~~~~~~~~~~~~~~~~~~
  mos is Open Storage Service provided by huawei.com
  http://www.hwclouds.com/
  """
  
  
  
  from docker_registry.core import dirver
  from docker_registry.core import exceptions
  from docker_registry.core import lru
  
  class Storage(dirver.Base):
      def __init__(self):
          pass
  
      def get_content(self, path):
          pass
  
      def put_content(self, path, content):
          """Method to put content."""
          pass
  
      def stream_read(self, path, bytes_range=None):
          """Method to stream read."""
          pass
      
      def stream_write(self, path, fp):
          """Method to stream write."""
          pass
  
      def list_directory(self, path=None):
          """Method to list directory."""
          pass
  
      def exists(self, path):
          """Method to test exists."""
          pass
  
      def remove(self, path):
          """Method to remove."""
         pass
  
      def get_size(self, path):
          """Method to get the size."""
          pass
  
subject: Update mos.py