'Get the latest live departure data for the specified stop.'

def _update(self):

    params = {'group': 'route', 'nextbuses': 'no'}
    self._do_api_request(params)
    if (self._data != {}):
        self._next_buses = []
        for (route, departures) in self._data['departures'].items():
            for departure in departures:
                if self._destination_re.search(departure['direction']):
                    self._next_buses.append({'route': route, 'direction': departure['direction'], 'scheduled': departure['aimed_departure_time'], 'estimated': departure['best_departure_estimate']})
        self._state = min(map(_delta_mins, [bus['scheduled'] for bus in self._next_buses]))
