@Test
public void icelandicLettersInAcroFieldTest() throws IOException, DocumentException, InterruptedException {

    String outFile = outFolder + "icelandicLettersInAcroFieldTest.pdf";
    FileOutputStream file = new FileOutputStream(outFile);
    PdfReader reader = new PdfReader(new FileInputStream(sourceFolder + "HelveticaFont.pdf"));
    PdfStamper stamper = new PdfStamper(reader, file);
    AcroFields fields = stamper.getAcroFields();
    fields.setField("Mitarbeiter", "ÁÁÁÁ ÓÓÓÓ Testð");
    stamper.close();
    CompareTool compareTool = new CompareTool();
    String errorMessage = compareTool.compareByContent(outFile, sourceFolder + "cmp_icelandicLettersInAcroFieldTest.pdf", outFolder, "diff_");
    if (errorMessage != null) {
        Assert.fail(errorMessage);
    }
}