docs: def key_tuple_value_nested_generator(dict_obj):
      """Recursively iterate over key-tuple-value pairs of nested dictionaries.
  
      Parameters
      ----------
      dict_obj : dict
          The outer-most dict to iterate on.
  
      Returns
      -------
      generator
          A generator over key-tuple-value pairs in all nested dictionaries.
  
      Example
      -------
      >>> dicti = {'a': 1, 'b': {'c': 3, 'd': 4}}
      >>> print(sorted(list(key_tuple_value_nested_generator(dicti))))
      [(('a',), 1), (('b', 'c'), 3), (('b', 'd'), 4)]
      """
      for key, value in dict_obj.items():
          if isinstance(value, dict):
              for nested_key, value in key_tuple_value_nested_generator(value):
                  yield tuple([key]) + nested_key, value
          else:
              yield tuple([key]), value