code: def wait_for_available_slots(self, min_num_proc, min_hosts=1):
      extra_message = (
          " An elastic job also requires that at least two hosts "
          "are available to resolve compatible network interfaces. If you know which interfaces "
          "are compatible in your network, set `--network-interface` to skip this check."
          if min_hosts > 1
          else ""
      )
  
      tmout = timeout.Timeout(
          self._timeout,
          message="Timed out waiting for {{activity}}. Please check that you have "
          f"enough resources to run at least {min_num_proc} Horovod processes.{extra_message}",
      )
  
      self._wait_hosts_cond.acquire()
      try:
          while True:
              current_hosts = self._host_manager.current_hosts
              avail_slots = current_hosts.count_available_slots()
              logging.debug(f"current available slots: {avail_slots}")
              avail_hosts = len(current_hosts.available_hosts)
              logging.debug(f"current available hosts: {avail_hosts}.")
              if (
                  avail_slots >= min_num_proc
                  and avail_hosts >= min_hosts
              ):
                  return current_hosts
              if self._shutdown.is_set():
                  raise RuntimeError(
                      "Job has been shutdown, see above error messages for details."
                  )
              self._wait_hosts_cond.wait(tmout.remaining())
              tmout.check_time_out_for(
                  "minimum number of slots to become available"
              )
      finally:
          self._wait_hosts_cond.release()
  
imports: import logging
  import os
  import queue
  import threading
  import time
  import warnings
  from collections import defaultdict
  from horovod.runner.common.util import hosts, timeout
  from horovod.runner.elastic.discovery import HostManager
  from horovod.runner.elastic.registration import WorkerStateRegistry
  from horovod.runner.elastic.worker import HostUpdateResult, WorkerNotificationClient
label_desc: Use image node_id 16 for calling the ElasticDriver obj's underlying member method code with example usage: obj.wait_for_available_slots(min_num_proc, min_hosts) and returns: current_hosts