public void setAbout(Attribute about) throws BadFieldValueException
    {
        if (XmpConstants.RDF_NAMESPACE.equals(about.getNamespace())
                && XmpConstants.ABOUT_NAME.equals(about.getName()))
        {
            setAttribute(about);
            return;
        }
        throw new BadFieldValueException("Attribute 'about' must be named 'rdf:about' or 'about'");
    }
@Test
    void testBadRdfAbout() throws Exception
    {
        assertThrows(BadFieldValueException.class, () -> {
            schem.setAbout(new Attribute(null, "about", ""));
        });
    }