class_docstr: A router to get the worker based on the partition ID.
code: def __init__(self, partition_to_workers: List[List[str]]):
      for pid, rpc_worker_list in enumerate(partition_to_workers):
          if len(rpc_worker_list) == 0:
              raise ValueError("No RPC worker is in worker list")
      self.partition_to_workers = partition_to_workers
      self.rpc_worker_indices = [
          0 for _ in range(len(partition_to_workers))
      ]
  
imports: import logging
  import threading
  from abc import ABC, abstractmethod
  from typing import Any, Callable, Dict, List, Optional
  from torch.distributed import rpc
  from torch_geometric.distributed.dist_context import DistContext, DistRole
label_desc: Use image node_id 1 to create a new RPCRouter object  with example: obj = RPCRouter(partition_to_workers)