code: def forward(self, x=None):
      if self._agg_layer is None:
          self._auto_setup()
  
      if self.device is None:
          self.device = self.get_device(self._top_model)
          self._agg_layer.set_device(self.device)
          if isinstance(self._agg_layer, SSHEAggLayerHost):
              if self.device.type != "cpu":
                  raise ValueError(
                      "SSHEAggLayerGuest is not supported on GPU"
                  )
  
      if self._bottom_model is None:
          b_out = None
      else:
          b_out = self._bottom_model(x)
          # bottom layer
          if not self._guest_direct_backward:
              self._bottom_fw = b_out
  
      # hetero layer
      if not self._guest_direct_backward:
          agg_out = self._agg_layer.forward(b_out)
          self._agg_fw_rg = agg_out.requires_grad_(True)
          # top layer
          top_out = self._top_model(self._agg_fw_rg)
      else:
          top_out = self._top_model(self._agg_layer(b_out))
  
      return top_out
  
imports: import torch
  import torch
  from fate.arch import Context
  from fate.ml.nn.model_zoo.agg_layer.agg_layer import AggLayerGuest, AggLayerHost
  from fate.ml.nn.model_zoo.agg_layer.fedpass.agg_layer import FedPassAggLayerGuest, FedPassAggLayerHost, get_model
  from fate.ml.nn.model_zoo.agg_layer.sshe.agg_layer import SSHEAggLayerHost, SSHEAggLayerGuest
  from typing import Any, Dict, List, Union, Callable, Literal
  from dataclasses import dataclass, fields
  from enum import Enum
  import logging
  from torch import device
label_desc: Use image node_id 7 for calling the HeteroNNModelGuest obj's underlying member method code with example usage: obj.forward(x) and returns: top_out