static boolean containsChildElement(final Packet stanza, final Set<String> elementNames, final String namespaceUriPrefix) {
        for (final String elementName : elementNames) {
            if (stanza.getElement().element(elementName) != null
             && stanza.getElement().element(elementName).getNamespaceURI() != null
             && stanza.getElement().element(elementName).getNamespaceURI().startsWith(namespaceUriPrefix)) {
                return true;
            }
        }
        return false;
    }
Checks if the provided stanza has a direct child element that matches any of the provided element names, escaped
by a namespace that <em>starts with</em> the provided prefix.

This method is intended to identify stanzas that have extensions for any version of a particular XEP.

@param stanza The stanza to check
@param elementNames The element names for which to search
@param namespaceUriPrefix Part of the namespace that identifies the element name.
@return true if matching child element is found, otherwise false.
xmppserver/src/main/java/org/jivesoftware/openfire/forward/Forwarded.java