private HelloWorld()
    {
    }
@Test
    void testHelloWorld() throws IOException
    {
        String outputDir = "target/test-output";
        String outputFile = outputDir + "/HelloWorld.pdf";
        String message = "HelloWorld.pdf";

        new File(outputFile).delete();

        String[] args = { outputFile, message };
        HelloWorld.main(args);

        checkOutputFile(outputFile, message);

        new File(outputFile).delete();
    }