class_docstr: A Munch that returns a user-specified value for missing keys.
code: def __repr__(self):
      return "{0}({1!r}, {2})".format(
          type(self).__name__, self.__undefined__, dict.__repr__(self)
      )
  
imports: from collections.abc import Mapping
label_desc: Use image node_id 9 for calling the DefaultMunch obj's underlying member method code with example usage: obj.__repr__() and returns: str