class_docstr: Explicitly coordinate the level Tornado components required to run a
  Bokeh server:
  
  * A Tornado ``IOLoop`` to run the Bokeh server machinery.
  
  * a ``BokehTornado`` Tornado application that defines the Bokeh server
    machinery.
  
  * a Tornado ``HTTPServer`` to direct HTTP requests
  
  All three of these components must be passed to ``BaseServer``, which will
  initialize the ``BokehTornado`` instance on the ``io_loop``. The
  ``http_server`` must have been previously created and initialized with the
  ``BokehTornado`` instance.
docstr: Create a ``BaseServer`` instance.
  
  Args:
      io_loop (IOLoop) :
          A Tornado ``IOLoop`` to run the Bokeh Tornado application on.
  
      tornado_app (BokehTornado) :
          An instance of the Bokeh Tornado application that generates
          Bokeh Documents and Sessions.
  
      http_server (HTTPServer) :
          A Tornado ``HTTPServer`` to service HTTP requests for Bokeh
          applications. Should have already be configured with the
          ``tornado_app`` when created.
docstr_tok: ["Create","a","``","BaseServer","``","instance",".","Args",":","io_loop","(","IOLoop",")",":","A","Tornado","``","IOLoop","``","to","run","the","Bokeh","Tornado","application","on",".","tornado_app","(","BokehTornado",")",":","An","instance","of","the","Bokeh","Tornado","application","that","generates","Bokeh","Documents","and","Sessions",".","http_server","(","HTTPServer",")",":","A","Tornado","``","HTTPServer","``","to","service","HTTP","requests","for","Bokeh","applications",".","Should","have","already","be","configured","with","the","``","tornado_app","``","when","created","."]
code: def __init__(
      self,
      io_loop: IOLoop,
      tornado_app: BokehTornado,
      http_server: HTTPServer,
  ) -> None:
      """Create a ``BaseServer`` instance.
  
      Args:
          io_loop (IOLoop) :
              A Tornado ``IOLoop`` to run the Bokeh Tornado application on.
  
          tornado_app (BokehTornado) :
              An instance of the Bokeh Tornado application that generates
              Bokeh Documents and Sessions.
  
          http_server (HTTPServer) :
              A Tornado ``HTTPServer`` to service HTTP requests for Bokeh
              applications. Should have already be configured with the
              ``tornado_app`` when created.
  
      """
  
      self._started = False
      self._stopped = False
  
      self._http = http_server
      self._loop = io_loop
      self._tornado = tornado_app
  
      self._tornado.initialize(io_loop)
  
imports: from __future__ import annotations
  import logging
  import atexit
  import signal
  import socket
  import sys
  from types import FrameType
  from typing import TYPE_CHECKING, Any, Mapping
  from tornado import netutil, version
  from tornado.httpserver import HTTPServer
  from tornado.ioloop import IOLoop
  from ..None import __version__
  from ..core import properties
  from ..core.properties import Bool, Int, Nullable, String
  from ..resources import DEFAULT_SERVER_PORT, server_url
  from ..util.options import Options
  from .tornado import DEFAULT_WEBSOCKET_MAX_MESSAGE_SIZE_BYTES, BokehTornado
  from .util import bind_sockets, create_hosts_allowlist
label_desc: Use image node_id 1 to create a new BaseServer object  with example: obj = BaseServer(io_loop, tornado_app, http_server)