static TestProfile processSourceFeatures(BiConsumer<SourceFeature, FeatureCollector> processFeature) {
      return new TestProfile(processFeature, (a) -> null, (a, b, c) -> c);
    }
In-memory tests with fake data and profiles to ensure all features work end-to-end.
planetiler-core/src/test/java/com/onthegomap/planetiler/PlanetilerTests.java