code: def _iter_subclasses(cls):
      yield cls
      for subcls in cls.__subclasses__():
          yield from _iter_subclasses(subcls)
  
imports: import contextlib
  import functools
  import inspect
  import weakref
  from collections import OrderedDict
  from funsor.registry import PartialDispatcher
  from funsor.util import methodof
label_desc: Use image node_id 3 for calling a global function with example usage: _iter_subclasses(cls) without return types