sectionOf method

K? sectionOf(K itemKey)

Implementation

K? sectionOf(K itemKey) {
  _checkNotDisposed();
  final parent = _tree.getParent(ItemKey<K>(itemKey));
  if (parent == null) {
    return null;
  }
  assert(
    parent is SectionKey<K>,
    "Item $itemKey has a non-section parent — tree invariant violated",
  );
  return (parent as SectionKey<K>).value;
}