code: def resolve_url(self, app, base_url: Optional[str] = None) -> None:
      for work in app.works:
          if (
              work.status.stage
              in (WorkStageStatus.RUNNING, WorkStageStatus.SUCCEEDED)
              and work._url == ""
              and work._port
          ):
              url = (
                  work._future_url
                  if work._future_url
                  else f"http://{work._host}:{work._port}"
              )
              if _check_service_url_is_ready(
                  url, metadata=f"Checking {work.name}"
              ):
                  work._url = url
  
imports: import multiprocessing
  from typing import Any, List, Optional
  import lightning.app
  from lightning.app.core import constants
  from lightning.app.core.queues import QueuingSystem
  from lightning.app.runners.backends.backend import Backend, WorkManager
  from lightning.app.utilities.enum import WorkStageStatus
  from lightning.app.utilities.network import _check_service_url_is_ready, find_free_network_port
  from lightning.app.utilities.port import disable_port, enable_port
  from lightning.app.utilities.proxies import ProxyWorkRun, WorkRunner
label_desc: Use image node_id 5 for calling the MultiProcessingBackend obj's underlying member method code with example usage: obj.resolve_url(app, base_url) without return types