code: def _start_sock(self, mux: StreamMux) -> int:
      address: str = self._address or "127.0.0.1"
      port: int = self._sock_port or 0
      self._sock_server = SocketServer(
          mux=mux, address=address, port=port
      )
      try:
          self._sock_server.start()
          port = self._sock_server.port
          if self._pid:
              mux.set_pid(self._pid)
      except KeyboardInterrupt:
          mux.cleanup()
          raise
      except Exception:
          mux.cleanup()
          raise
      return port
  
file_path: wandb/wandb/sdk/service/server.py
imports: import logging
  import os
  import sys
  from typing import Optional
  import wandb
  from ..lib import tracelog
  from .None import _startup_debug, port_file
  from .server_sock import SocketServer
  from .streams import StreamMux
label_desc: Use image node_id 3 for calling the WandbServer obj's underlying member method code with example usage: obj._start_sock(mux) and returns: port