@Override
  public FieldType findFieldType(String messageType, String fieldName) {
    com.google.api.expr.v1alpha1.Type type = switch (messageType) {
      case GeometryVal.NAME -> GeometryVal.fieldType(fieldName);
      case null, default -> null;
    };
    return type == null ? null : new FieldType(type, any -> false, any -> null);
  }
Registers any types that are available to CEL expressions in planetiler configs.
planetiler-custommap/src/main/java/com/onthegomap/planetiler/custommap/expression/stdlib/PlanetilerTypeRegistry.java