private static double length(List<Coordinate> edge) {
    Coordinate last = null;
    double length = 0;
    for (Coordinate coord : edge) {
      if (last != null) {
        length += last.distance(coord);
      }
      last = coord;
    }
    return length;
  }
Processes the added geometries and returns the merged linestrings.
<p>
Can be called more than once.
planetiler-core/src/main/java/com/onthegomap/planetiler/util/LoopLineMerger.java