docs: def to_jsonf(self, fpath: str, encoding: str='utf8', indent: int=None, ignore_none: bool=True, ignore_empty: bool=False) -> str:
          """From instance to json file
  
          :param fpath: Json file path
          :param encoding: Json file encoding
          :param indent: Number of indentation
          :param ignore_none: Properties which is None are excluded if True
          :param ignore_empty: Properties which is empty are excluded if True
          :return: Json file path
          """
          return util.save_jsonf(traverse(self, ignore_none, force_value=True, ignore_empty=ignore_empty), fpath, encoding, indent)