Add new custom element.

def define(self, *args: Any, **kwargs: Any) -> None:
        """Add new custom element."""
        if isinstance(args[0], str):
            self._define_orig(*args, **kwargs)
        elif isinstance(args[0], type):
            self._define_class(*args, **kwargs)
        else:
            raise TypeError(
                'Invalid argument for define: {}, {}'.format(args, kwargs))