code: def __call__(self, *args, **kwargs):
      arg = self.weak_arg()
      return self.fn(arg, *args, **kwargs)
  
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 2 for calling the WeakPartial obj's underlying member method code with example usage: obj.__call__() and returns: self