'Moves trainer towards a fort before a Pokemon.
Args:
fort
Returns:
StepWalker'

def _move_to_pokemon_througt_fort(self, fort, pokemon):

    nearest_fort = fort
    lat = nearest_fort[u'latitude']
    lng = nearest_fort[u'longitude']
    fortID = nearest_fort[u'id']
    details = fort_details(self.bot, fortID, lat, lng)
    fort_name = details.get(u'name', u'Unknown')
    unit = self.bot.config.distance_unit
    dist = distance(self.bot.position[0], self.bot.position[1], lat, lng)
    if (dist > Constants.MAX_DISTANCE_FORT_IS_REACHABLE):
        pokemon_throught_fort_event_data = {u'fort_name': u'{}'.format(fort_name), u'distance': format_dist(dist, unit), u'poke_name': pokemon[u'name'], u'poke_dist': format_dist(pokemon[u'dist'], self.unit)}
        self.emit_event(u'moving_to_pokemon_throught_fort', formatted=u'Moving    towards    {poke_name}    -    {poke_dist}        through    pokestop        {fort_name}    -    {distance}', data=pokemon_throught_fort_event_data)
    else:
        self.emit_event(u'arrived_at_fort', formatted=u'Arrived    at    fort.')
    return walker_factory(self.walker, self.bot, lat, lng)
