public FeaturePostMatch createPostMatchContext(List<String> matchKeys) {
      return new FeaturePostMatch(this, matchKeys);
    }
Context available when processing an input feature.

@param feature          The input feature being processed
@param tagValueProducer Common parsing for input feature tags
planetiler-custommap/src/main/java/com/onthegomap/planetiler/custommap/Contexts.java