* since it could potentially use a tag already used in the parent
* memento and thus overwrite data.
*/
IMemento persistableMemento = memento
.createChild(IWorkbenchConstants.TAG_PERSISTABLE);
persistable.saveState(persistableMemento);
memento.putString(IWorkbenchConstants.TAG_FACTORY_ID,
persistable.getFactoryId());
if (descriptor != null && descriptor.getId() != null) {
memento.putString(IWorkbenchConstants.TAG_ID, descriptor
.getId());