new_contents: from __future__ import absolute_import, unicode_literals
  
  
  class RemovedInWagtailMenus24Warning(DeprecationWarning):
      pass
  
  
  removed_in_next_version_warning = RemovedInWagtailMenus24Warning
  
  
  class RemovedInWagtailMenus25Warning(PendingDeprecationWarning):
      pass
  
subject: Add some wagtailmenus-specific deprecation warnings to wagtailmenus.utils.deprecation to be used within the project