llm=RealtimeModelFallbackAdapter(
 [openai.realtime.RealtimeModel(),
openai.realtime.RealtimeModel.with_azure()]
)

def attach_oai_realtime_event_handlers(self, rt_session: RealtimeSession) -> None:
  if not isinstance(rt_session, livekit.plugins.openai.realtime.realtime_model.RealtimeSession:
     raise TypeError(f"Expected OpenAI RealtimeSession, got {type(rt_session).__name__}")

    @rt_session.on("openai_server_event_received")
    def on_openai_server_event_received(event: dict[str, Any]) -> None:
          pass

if type(rt_session).__name__ == "_FallbackRealtimeSession":
  current_child_session = rt_session._active
  @rt_session.on("session_reconnected")
  def on_session_reconnected(_: RealtimeSessionReconnectedEvent) -> None:
      nonlocal current_child_session
      new_child_session = rt_session._active 
      # check whether the new child session is different from the current child session
      # to make sure the received 'session_reconnected' event is emitted by model fallback
      if new_child_session is not current_child_session:
          LOGGER.info(
              "Resubscribe OpenAI realtime event handlers when model fallback happens "
              "for RealtimeFallbackAdapter"
          )
          attach_oai_realtime_event_handlers(new_child_session)
          current_child_session = new_child_session