message: MultiProcessRunner: Supplement timeout information and what users can do to increase that.
diff: @@ -612,7 +612,11 @@ class MultiProcessRunner(object):
  self._watchdog_thread.join()
  process_statuses = self._get_process_statuses()
  self._reraise_if_subprocess_error(process_statuses)
  - raise SubprocessTimeoutError('one or more subprocesses timed out.',
  + raise SubprocessTimeoutError(
  + 'One or more subprocesses timed out, where timeout was set to {}s. '
  + 'Please change the `timeout` argument for '
  + '`MultiProcessRunner.join()` or `multi_process_runner.run()` '
  + 'if it should be adjusted.'.format(timeout),
  self._get_mpr_result(process_statuses))
  for (task_type, task_id), p in self._processes.items():
  