def has_next(self):
return self._payload_list.has_next()<EOL>
Tests if there are more elements in this list.

        return: (boolean) - ``true`` if more elements are available in
                this list, ``false`` if the end of the list has been
                reached
        *compliance: mandatory -- This method must be implemented.*
        *implementation notes*: Any errors that may result from accesing
        the underlying set of elements are to be deferred until the
        consumer attempts retrieval in which case the provider must
        return ``true`` for this method.