effectiveItems property
All the PaneItems inside allItems
Items with null body are excluded as they are not navigable
(e.g., PaneItemExpander without a body that only expands/collapses).
Implementation
List<PaneItem> get effectiveItems {
return allItems
.where((i) => i is PaneItem && i is! PaneItemAction && i.body != null)
.cast<PaneItem>()
.toList();
}