docstr: Waits for the background process to finish running. Waits until the
  background process has run for at least `timeout` seconds, counting from
  the time when the process was started.
docstr_tok: ["Waits","for","the","background","process","to","finish","running",".","Waits","until","the","background","process","has","run","for","at","least","`","timeout","`","seconds",",","counting","from","the","time","when","the","process","was","started","."]
code: def wait(self, timeout: Optional[float] = None) -> Any:
      """Waits for the background process to finish running. Waits until the
      background process has run for at least `timeout` seconds, counting from
      the time when the process was started."""
      if not self._process:
          return None
  
      time_remaining = None
      if timeout:
          elapsed = time.time() - self.start_time
          time_remaining = max(timeout - elapsed, 0)
  
      self._process.join(timeout=time_remaining)
  
      if self._process.is_alive():
          self._process = None
          raise TimeoutError(
              f"{getattr(self._fn, '__name__', str(self._fn))} did not finish "
              f"running within the timeout of {timeout} seconds."
          )
  
      self._process = None
  
      exception = self._result.get("exception")
      if exception:
          raise exception
  
      result = self._result.get("result")
  
      self._result = {}
      return result
  
imports: import abc
  import logging
  import threading
  import time
  import traceback
  import warnings
  from dataclasses import dataclass
  from typing import Any, Callable, Dict, List, Optional, Tuple, Union
  from ray._private.thirdparty.tabulate.tabulate import tabulate
  from ray.train.constants import _DEPRECATED_VALUE
  from ray.util import log_once
  from ray.util.annotations import PublicAPI
  from ray.widgets import Template
label_desc: Use image node_id 5 for calling the _BackgroundProcess obj's underlying member method code with example usage: obj.wait(timeout) and returns: result, None