class_docstr: A Munch that returns a user-specified value for missing keys.
code: def __setattr__(self, k, v):
      if k == "__default__":
          object.__setattr__(self, k, v)
      else:
          super(DefaultMunch, self).__setattr__(k, v)
  
imports: from collections.abc import Mapping
label_desc: Use image node_id 3 for calling the DefaultMunch obj's underlying member method code with example usage: obj.__setattr__(k, v) without return types