public Feature geometry(String layer, Geometry geometry) {
    // TODO args could also provide a list of source IDs to put into slot 4, 5, 6, etc..
    // to differentiate between other sources besides just OSM and "other"
    long vectorTileId = config.featureSourceIdMultiplier() < 4 ? source.id() :
      source.vectorTileFeatureId(config.featureSourceIdMultiplier());
    Feature feature = new Feature(layer, geometry, vectorTileId);
    output.add(feature);
    return feature;
  }
Starts building a new map feature with an explicit JTS {@code geometry} that overrides the source geometry.

@param layer    the output vector tile layer this feature will be written to
@param geometry the explicit geometry to use instead of what is present in source data
@return a feature that can be configured further.
planetiler-core/src/main/java/com/onthegomap/planetiler/FeatureCollector.java