// and extensionObjects are null and the Extension is cointained by the ExtensionMap then
// remove it form the list.
Extension extension = (Extension) notification.getNotifier();
if(extension.getExtendedObject() == null && extension.getExtensionObject() == null &&
extension.eContainer() != null){
ExtensionMap extensionSet = (ExtensionMap)extension.eContainer();
if(extensionSet != null && extensionSet.getExtensions().contains(extension))
extensionSet.getExtensions().remove(extension);