code: def __call__(self, env, start_resp):
      if not self.running:
          raise RuntimeError("not started")
      assert self._app
      return self._app(env, start_resp)
  
imports: import json
  import logging
  import math
  import os
  import socket
  import subprocess
  import sys
  import threading
  import time
  from werkzeug.exceptions import NotFound
  from werkzeug.utils import redirect
  from guild import serving_util
  from guild import util
  from guild import var
label_desc: Use image node_id 6 for calling the TBServer obj's underlying member method code with example usage: obj.__call__(env, start_resp) and returns: self