private static OutputFormat getOutputFormat(SchemaType outputType) {
    return switch (outputType) {
      case DTD -> new DtdOutputFormat();
      case RNC -> new RncOutputFormat();
      case RNG -> new RngOutputFormat();
      case XSD -> new XsdOutputFormat();
      default -> {
        assert false : "Unsupported output type: " + outputType;
        yield null;
      }
    };
  }
private static OutputFormat getOutputFormat(SchemaType outputType)