class_docstr: A function cache based on code objects.
  
  Code objects are good proxies for the source code of a function.
  
  This cache efficiently handles functions that share code objects, such as
  functions defined in a loop, bound methods, etc.
  
  The cache falls back to the function object, if it doesn't have a code object.
code: def _get_key(self, entity):
      if hasattr(entity, "__code__"):
          return entity.__code__
      else:
          return entity
  
file_path: DALI/dali/python/nvidia/dali/_autograph/pyct/cache.py
imports: import inspect
  import weakref
label_desc: Use image node_id 1 for calling the CodeObjectCache obj's underlying member method code with example usage: obj._get_key(entity) and returns: entity, entity