code: function _addTrip(trip) {
  
      // Make sure trip isn't already in list
      let found = false;
      for ( let i = 0; i < rtn.length; i++ ) {
        if ( rtn[i].id === trip.id ) {
          found = true;
        }
      }
  
      // Process new trip
      if ( !found ) {
  
        // Make sure the trip stops at any of the next stops, after the current stop
        let stopFound = false;
        let add = false;
        for ( let i = 0; i < trip.stopTimes.length; i++ ) {
          let stopId = trip.stopTimes[i].stop.id;
          if ( !stopFound && stopId === stop.id ) {
            stopFound = true;
          }
          else if ( stopFound ) {
            if ( nextStops.indexOf(stopId) > -1 ) {
              add = true;
              i = trip.stopTimes.length;
            }
          }
        }
  
        // Add Trip
        if ( add ) {
          rtn.push(trip);
        }
  
      }
  
    }
docs: Add the specified Trip to the return list, if it is not
  already present and it continues to one of the next stops
  @param {Trip} trip Trip to add
  @private