// Copy non-conflicting elements from old config element
for (final PluginElement child : prev.getChildren()) {
if (!(child instanceof ConfigurationElement)) {
// configElem should only contain other ConfigurationElemnents, so
// this case is non-conflicting
retVal.addChild(child);
}
else {
final ConfigurationElement oldChild = ConfigurationElement.class.cast(child);
if (!configElem.hasChildByName(oldChild.getName(), true))
retVal.addChild(oldChild);