'Checks if the given tracker URL should be checked right now or not.
:param tracker_url: The given tracker URL.
:return: True or False.'

@call_on_reactor_thread
def should_check_tracker(self, tracker_url):

    current_time = int(time.time())
    tracker_info = self._tracker_dict.get(tracker_url, {u'is_alive': True, u'last_check': 0, u'failures': 0})
    next_check_time = (tracker_info[u'last_check'] + (self._tracker_retry_interval * (2 ** tracker_info[u'failures'])))
    return (next_check_time <= current_time)
