code: def model_aggregation(self, ctx, ranks=None):
      self.model_aggregator.secure_aggregate(ctx, ranks=ranks)
  
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 5 for calling the BaseAggregatorServer obj's underlying member method code with example usage: obj.model_aggregation(ctx, ranks) without return types