old_contents: """A dummy contents manager for when the logic is done client side (in JavaScript)."""
  
  # Copyright (c) IPython Development Team.
  # Distributed under the terms of the Modified BSD License.
  
  from IPython.html.services.contents.manager import ContentsManager
  from IPython.html.services.contents.filemanager import FileContentsManager
  
  class ClientSideContentsManager(ContentsManager):
      """Dummy contents manager for use with client-side contents APIs like GDrive
  
      The view handlers for notebooks and directories (/tree/) check with the
      ContentsManager that their target exists so they can return 404 if not. Using
      this class as the contents manager allows those pages to render without
      checking something that the server doesn't know about.
      """
      def dir_exists(self, path):
          return True
  
      def is_hidden(self, path):
          return False
  
      def file_exists(self, path=''):
          return True
  
      def get(self, path, content=True, type=None, format=None):
          ## if ends with ipynb
          return {'type':'notebook'}
  
new_contents: """A dummy contents manager for when the logic is done client side (in JavaScript)."""
  
  # Copyright (c) IPython Development Team.
  # Distributed under the terms of the Modified BSD License.
  
  try:
      from jupyter_notebook.services.contents.manager import ContentsManager
      from jupyter_notebook.services.contents.filemanager import FileContentsManager
  except ImportError:
      from IPython.html.services.contents.manager import ContentsManager
      from IPython.html.services.contents.filemanager import FileContentsManager
  
  class ClientSideContentsManager(ContentsManager):
      """Dummy contents manager for use with client-side contents APIs like GDrive
  
      The view handlers for notebooks and directories (/tree/) check with the
      ContentsManager that their target exists so they can return 404 if not. Using
      this class as the contents manager allows those pages to render without
      checking something that the server doesn't know about.
      """
      def dir_exists(self, path):
          return True
  
      def is_hidden(self, path):
          return False
  
      def file_exists(self, path=''):
          return True
  
      def get(self, path, content=True, type=None, format=None):
          ## if ends with ipynb
          return {'type':'notebook'}
  
subject: fix import in jupyter