code: def __call__(self):
      return self.default
  
imports: from collections import defaultdict
  from multipledispatch.dispatcher import Dispatcher, expand_tuples
  from funsor.typing import Variadic, deep_type, get_origin, get_type_hints, typing_wrap
label_desc: Use image node_id 2 for calling the PartialDefault obj's underlying member method code with example usage: obj.__call__() and returns: self