updateSection method

void updateSection(K sectionKey, Section section)

Updates sectionKey's payload to section without touching the section's items. Asserts that sectionKey already exists.

The key is taken explicitly rather than inferred from sectionKeyOf(section) so that a copy-with that nudges the id field surfaces as a missing-key assertion instead of silently corrupting the tree.

Implementation

void updateSection(K sectionKey, Section section) {
  _checkNotDisposed();
  _requireSection(sectionKey, "updateSection");
  _tree.updateNode(
    TreeNode(
      key: SectionKey<K>(sectionKey),
      data: SectionPayload<Section, Item>(section),
    ),
  );
}