def process_tick(self, tup):
pass<EOL>
Process special 'tick Tuples' which allow time-based
        behaviour to be included in bolts.

        Default behaviour is to ignore time ticks.  This should be
        overridden by subclasses who wish to react to timer events
        via tick Tuples.

        Tick Tuples will be sent to all bolts in a toplogy when the
        storm configuration option 'topology.tick.tuple.freq.secs'
        is set to an integer value, the number of seconds.

        :param tup: the Tuple to be processed.
        :type tup: :class:`pystorm.component.Tuple`