public static IQ iqFrom(final String stanza) {
        try {
            final SAXReader reader = new SAXReader();
            final Document document = reader.read(new ByteArrayInputStream(stanza.getBytes(StandardCharsets.UTF_8)));
            return new IQ(document.getRootElement());
        } catch (final DocumentException e) {
            throw new IllegalArgumentException("The supplied input did not contain a well-formed XML document", e);
        }
    }
As {@link #reconfigureOpenfireHome()} allows properties to persist, this method clears all existing properties
(both XML and 'database') to ensure clean test output. Ideally should be called in a {@link org.junit.Before} method.

@param except properties that are not cleared if they are set.
xmppserver/src/test/java/org/jivesoftware/Fixtures.java