old_contents: # -*- coding: utf-8 -*-
  
  __all__ = ['categories', 'manager', 'filesystems']
  
  from . import categories
  from . import manager
  from . import filesystems
  
new_contents: # -*- coding: utf-8 -*-
  
  __all__ = ['categories', 'plugin_manager', 'filesystems']
  
  from . import categories
  from . import plugin_manager
  from . import filesystems
  
subject: update init