code: def undoc(func):
      """Mark a function or class as undocumented.
  
      This is found by inspecting the AST, so for now it must be used directly
      as @undoc, not as e.g. @decorators.undoc
      """
      return func
  
imports: from typing import Sequence
  from IPython.utils.docs import GENERATING_DOCUMENTATION
label_desc: Use image node_id 2 for calling a global function with example usage: undoc(func) and returns: func