code: def backbone(self):
      return self._backbone
  
imports: from collections import OrderedDict
  from typing import Dict
  import torch
  import torch.nn
  from einops import rearrange
  from omegaconf import DictConfig
  from pytorch_tabular.models.common.layers.batch_norm import BatchNorm1d
  from ..base_model import BaseModel
  from ..common.layers import Embedding2dLayer, TransformerEncoderBlock
label_desc: Use image node_id 2 for calling the TabTransformerModel obj's underlying member method code with example usage: obj.backbone() and returns: self