docs: public LineString getTripGeometry(String trip_id){
  
          CoordinateList coordinates = new CoordinateList();
          LineString ls = null;
          Trip trip = trips.get(trip_id);
  
          // If trip has shape_id, use it to generate geometry.
          if (trip.shape_id != null) {
              Shape shape = getShape(trip.shape_id);
              if (shape != null) ls = shape.geometry;
          }
  
          // Use the ordered stoptimes.
          if (ls == null) {
              ls = getStraightLineForStops(trip_id);
          }
  
          return ls;
      }