code: def get_backbone(
      model_name: str, root: str = get_model_zoo_home_dir(), **kwargs
  ) -> Tuple["Block", str, BaseTokenizer, str, List]:
      """Get the backbone network
  
      Parameters
      ----------
      model_name
          The name of the pretrained model
      root
          Downloaded directory of the model zoo
  
      Returns
      -------
      model_cls
          The class to construct the backbone network
      cfg
          Path to the config file of the backbone
      tokenizer
          The tokenizer that is bound to the backbone model
      backbone_param_path
          The path to the pretrained backbone weights
      others
          The other items returned by the create function.
           Will be wrapped into a list
  
      Examples
      --------
  
      >>> from gluonnlp.models import get_backbone
      >>> model_cls, cfg, tokenizer, backbone_param_path, _ = get_backbone('google_en_cased_bert_base')
      >>> model = model_cls.from_cfg(cfg)
      >>> model.load_parameters(backbone_param_path)
      """
      model_cls, local_create_fn = None, None
  
      for backbone_type in BACKBONE_REGISTRY.list_keys():
          (
              ele_model_cls,
              ele_local_create_fn,
              list_key_fn,
          ) = BACKBONE_REGISTRY.get(backbone_type)
          if model_name in list_key_fn():
              model_cls = ele_model_cls
              local_create_fn = ele_local_create_fn
      if model_cls is None or local_create_fn is None:
          raise KeyError(
              'The backbone model "{}" is not found! '
              "Here are all available backbone models = {}".format(
                  model_name, list_backbone_names()
              )
          )
      cfg, tokenizer, local_params_path, *others = local_create_fn(
          model_name=model_name, root=root, **kwargs
      )
      return model_cls, cfg, tokenizer, local_params_path, others
  
imports: from typing import Tuple, List
  from ..base import get_model_zoo_home_dir
  from ..data.tokenizers import BaseTokenizer
  from ..utils.registry import Registry
  from mxnet.gluon import Block
label_desc: Use image node_id 2 for calling a global function with example usage: get_backbone(model_name, root) and returns: model_cls,  cfg,  tokenizer,  local_params_path,  others