text: import os
  import sys
  
  import terminado
  from ..utils import check_version
  
  if not check_version(terminado.__version__, '0.8.3'):
      raise ImportError(f"terminado >= 0.8.3 required, found {terminado.__version__}")
  
  from ipython_genutils.py3compat import which
  from notebook.utils import url_path_join as ujoin
  from .terminalmanager import TerminalManager
  from .handlers import TerminalHandler, TermSocket, NewTerminalHandler, NamedTerminalHandler
  from . import api_handlers
  
  
  def initialize(nb_app):
      if os.name == 'nt':
          default_shell = 'powershell.exe'
      else:
          default_shell = which('sh')
      shell_override = nb_app.terminado_settings.get('shell_command')
      shell = (
          [os.environ.get('SHELL') or default_shell]
          if shell_override is None
          else shell_override
      )
      # When the notebook server is not running in a terminal (e.g. when
      # it's launched by a JupyterHub spawner), it's likely that the user
      # environment hasn't been fully set up. In that case, run a login
      # shell to automatically source /etc/profile and the like, unless
      # the user has specifically set a preferred shell command.
      if os.name != 'nt' and shell_override is None and not sys.stdout.isatty():
          shell.append('-l')
      terminal_manager = nb_app.web_app.settings['terminal_manager'] = TerminalManager(
          shell_command=shell,
          extra_env={'JUPYTER_SERVER_ROOT': nb_app.notebook_dir,
                     'JUPYTER_SERVER_URL': nb_app.connection_url,
                     },
          parent=nb_app,
      )
      terminal_manager.log = nb_app.log
      base_url = nb_app.web_app.settings['base_url']
      handlers = [
          (ujoin(base_url, r"/terminals/new"), NamedTerminalHandler),
          (ujoin(base_url, r"/terminals/new/(\w+)"), NewTerminalHandler),
          (ujoin(base_url, r"/terminals/(\w+)"), TerminalHandler),
          (ujoin(base_url, r"/terminals/websocket/(\w+)"), TermSocket,
               {'term_manager': terminal_manager}),
          (ujoin(base_url, r"/api/terminals"), api_handlers.TerminalRootHandler),
          (ujoin(base_url, r"/api/terminals/(\w+)"), api_handlers.TerminalHandler),
      ]
      nb_app.web_app.add_handlers(".*$", handlers)
  