Add duplicate trip check?

[landonreed]

In the OverlappingTripValidator there is some commented out code that looks to be checking for duplicate trips. There is a comment that mentions that this error type appears to be just a subset of the overlapping trips in block check. I have moved this code to this issue in case further action needs to be taken.

    // FIXME what is this patternId? This seems like a subset of block overlap errors (within a service day).
//            String patternId = feed.tripPatternMap.get(tripId);
//            String patternName = feed.patterns.get(patternId).name;
//            int firstDeparture = Iterables.get(stopTimes, 0).departure_time;
//            int lastArrival = Iterables.getLast(stopTimes).arrival_time;
//
//            String tripKey = trip.service_id + "_"+ blockId + "_" + firstDeparture +"_" + lastArrival + "_" + patternId;
//
//            if (duplicateTripHash.containsKey(tripKey)) {
//                String firstDepartureString = LocalTime.ofSecondOfDay(Iterables.get(stopTimes, 0).departure_time % 86399).toString();
//                String lastArrivalString = LocalTime.ofSecondOfDay(Iterables.getLast(stopTimes).arrival_time % 86399).toString();
//                String duplicateTripId = duplicateTripHash.get(tripKey);
//                Trip duplicateTrip = feed.trips.get(duplicateTripId);
//                long line = trip.id > duplicateTrip.id ? trip.id : duplicateTrip.id;
//                feed.errors.add(new DuplicateTripError(trip, line, duplicateTripId, patternName, firstDepartureString, lastArrivalString));
//                isValid = false;
//            } else {
//                duplicateTripHash.put(tripKey, tripId);
//            }