src/main/java/com/conveyal/gtfs/GTFSFeed.java
public List<Trip> getDistinctTripsForStop (String stop_id) {
        return getStopTimesForStop(stop_id).stream()
                .map(stopTime -> this.trips.get(stopTime.trip_id))
                .distinct()
                .collect(Collectors.toList());
    }
public List<Trip> getDistinctTripsForStop (String stop_id) {
        return getStopTimesForStop(stop_id).stream()
                .map(stopTime -> this.trips.get(stopTime.trip_id))
                .distinct()
                .collect(Collectors.toList());
    }
Get list of distinct trips (filters out multiple visits by a trip) a given stop_id.