code: def _register_formats(cls):
          
          for fmt in cls.OUTPUT_FORMATS:
              clean_fmt = fmt.replace('+', '_')
              setattr(cls, clean_fmt, property(
                  (lambda x, fmt=fmt: cls._output(x, fmt)), # fget
                  (lambda x, y, fmt=fmt: cls._input(x, y, fmt))))
docs: Adds format properties.