code: def dummy_context_manager():
      """Dummy context manager"""
      yield None
  
file_path: deepchem/deepchem/utils/differentiation_utils/misc.py
imports: import contextlib
  import copy
  from typing import Mapping, Callable, Union, Dict, List
label_desc: Use image node_id 4 for calling a global function with example usage: dummy_context_manager() without return types