old_contents: from .oauth2 import *
  from .github import *
  from .gitlab import *
  from .bitbucket import *
  from .google import *
  
  from ._version import __version__, version_info
  
new_contents: # include github, bitbucket, google here for backward-compatibility
  # don't add new oauthenticators here.
  from .oauth2 import *
  from .github import *
  from .bitbucket import *
  from .google import *
  
  from ._version import __version__, version_info
  
subject: remove gitlab from top-level