private void recordLayerDiff(TileCoord coord, String layer, String issue) {
    var layerDiffs = diffsByLayer.get(layer);
    if (layerDiffs == null) {
      layerDiffs = diffsByLayer.computeIfAbsent(layer, k -> new ConcurrentHashMap<>());
    }
    layerDiffs.merge(issue, 1L, Long::sum);
    if (verbose) {
      LOGGER.debug("{} layer {} {}", coord, layer, issue);
    }
  }
@throws FatalComparisonFailure if a comparison failure is encountered that prevents comparing the whole archives.
planetiler-core/src/main/java/com/onthegomap/planetiler/util/CompareArchives.java