code: def _check_party_id(self, party_id):
      # party idx >= -1, int
      if not isinstance(party_id, int):
          raise ValueError("party_id should be int")
      if party_id < -1:
          raise ValueError("party_id should be greater than -1")
  
imports: import logging
  from typing import Optional
  import numpy
  import torch
  from fate.arch import Context
  from fate.arch.protocol.secure_aggregation._secure_aggregation import SecureAggregatorClient
  from fate.arch.protocol.secure_aggregation._secure_aggregation import SecureAggregatorServer
label_desc: Use image node_id 2 for calling the BaseAggregatorServer obj's underlying member method code with example usage: obj._check_party_id(party_id) without return types