code: def _devserver_bin():
      path = os.path.join(
          MODULE_DIR, "view/node_modules/.bin/webpack-dev-server"
      )
      if not os.path.exists(path):
          raise AssertionError(
              f"{path} does not exits - did you resolve node dependencies by "
              "running npm install?"
          )
      return path
  
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 4 for calling the DevServer obj's underlying member method code with example usage: obj._devserver_bin() and returns: path