code: def forward(self, x):
      if self._model is None:
          raise RuntimeError(
              "Model is not initialized! Call set_context to initialize ctx and model"
          )
      fake_loss = self._model(x)
      return fake_loss
  
imports: from typing import Union, Literal, Tuple
  import torch
  from fate.arch import Context
  from fate.ml.nn.model_zoo.agg_layer.agg_layer import _AggLayerBase
  from fate.arch.protocol.mpc.nn.sshe.nn_layer import SSHENeuralNetworkAggregatorLayer, SSHENeuralNetworkOptimizerSGD
label_desc: Use image node_id 5 for calling the SSHEAggLayerHost obj's underlying member method code with example usage: obj.forward(x) and returns: fake_loss