<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def navigation(self, id=None):
 """Function decorator for navbar registration. Convenience function, calls :meth:`.register_element` with ``id`` and the decorated function as ``elem``. :param id: ID to pass on. If ``None``, uses the decorated functions name. """


        def wrapper(f):
            self.register_element(id or f.__name__, f)
            return f

        return wrapper