class_docstr: A Munch that calls a user-specified function to generate values for
  missing keys like collections.defaultdict.
  
  >>> b = DefaultFactoryMunch(list, {'hello': 'world!'})
  >>> b.hello
  'world!'
  >>> b.foo
  []
  >>> b.bar.append('hello')
  >>> b.bar
  ['hello']
code: def fromDict(cls, d, default_factory):
      # pylint: disable=arguments-differ
      return munchify(d, factory=lambda d_: cls(default_factory, d_))
  
imports: from collections.abc import Mapping
label_desc: Use image node_id 2 for calling the DefaultFactoryMunch obj's underlying member method code with example usage: obj.fromDict(cls, d, default_factory) and returns: munchify