code: def backbone(self):
      return self._backbone
  
file_path: pytorch_tabular/src/pytorch_tabular/models/category_embedding/category_embedding_model.py
imports: import torch
  import torch.nn
  from omegaconf import DictConfig
  from pytorch_tabular.models.common.layers import Embedding1dLayer
  from pytorch_tabular.utils import _initialize_layers, _linear_dropout_bn
  from ..base_model import BaseModel
label_desc: Use image node_id 2 for calling the CategoryEmbeddingModel obj's underlying member method code with example usage: obj.backbone() and returns: self