@Test
public void clipFieldNotSignature() {

    dictionary.setItem(COSName.FT, COSName.BTN);
    PDField field = PDFieldFactory.createFieldAddingChildToParent(new PDAcroForm(new PDDocument()), dictionary,
            null);
    SignatureClipper.clipSignature(field);
    assertTrue(field.getCOSObject().containsKey(COSName.V));
    assertTrue(field.getCOSObject().containsKey(COSName.SV));
    assertTrue(field.getCOSObject().containsKey(COSName.LOCK));
}