class_docstr: WSGI server for notebook environments.
class_docstr_tok: ["WSGI","server","for","notebook","environments","."]
code: def app(self):
      return self._app
  
imports: import socket
  import threading
  from typing import Optional
  from wsgiref import validate
  import wsgiref.simple_server
  from absl import logging
  import portpicker
  import termcolor
  from werkzeug import serving
label_desc: Use image node_id 2 for calling the NotebookWsgiServer obj's underlying member method code with example usage: obj.app() and returns: self