public Map<String, List<String>> dependsOnLayer() {
    return Map.of();
  }
Indicate to {@link #caresAboutLayer(String)} what layers (dependents) rely on other layers (dependencies) so that
methods like {@link #registerFeatureHandler(FeatureProcessor)}, {@link #registerHandler(Handler)} or
{@link #registerSourceHandler(String, FeatureProcessor)} do not block registration of those dependencies.
<p>
Dependencies are described as a map with dependent layer names as keys and lists containing dependency layer names
as map values. Example: Layer named {@code transportation_name} depends on layer named {@code transportation}:
<p>
{@snippet :
Map.of("transportation_name", List.of("transportation"));
}

@return a map describing dependencies
planetiler-core/src/main/java/com/onthegomap/planetiler/ForwardingProfile.java