code: def get(key: Optional[str] = None) -> "ModelLoader":
      if key is None:
          return DefaultLoader()
      else:
          raise ValueError(f"No model loader for: {key}")
  
file_path: foolbox/foolbox/zoo/model_loader.py
imports: from typing import Any, cast, Optional
  from types import ModuleType
  import sys
  import importlib
  import abc
  from abc import abstractmethod
  from ..models import Model
label_desc: Use image node_id 2 for calling the ModelLoader obj's underlying member method code with example usage: obj.get(key) and returns: DefaultLoader