@SuppressWarnings("unchecked") @Override public Object getParent(Object itemId) { return getTreeDatasource().getParent((K) itemId); }
@Nullable @Override public E getParent(E item) { Preconditions.checkNotNullArgument(item); K parentId = datasource.getParent(item.getId()); return datasource.getItem(parentId); }
@Nullable @Override public E getParent(E item) { Preconditions.checkNotNullArgument(item); K parentId = getHierarchicalDatasource().getParent(item.getId()); return getHierarchicalDatasource().getItem(parentId); } }