message: better use of StateSelection API
diff: @@ -186,12 +186,8 @@ export const SelectLoci = PluginBehavior.create({
  Structure.areEquivalent(structure, oldStructure) &&
  Structure.areHierarchiesEqual(structure, oldStructure)) return;
  - const children = this.ctx.state.data.select(StateSelection.children(ref));
  - for (const child of children) {
  - if (child.obj?.type === SO.Molecule.Structure.Representation3D.type) {
  - this.applySelectMark(child.transform.ref, true);
  - }
  - }
  + const reprs = this.ctx.state.data.select(StateSelection.children(ref).ofType(SO.Molecule.Structure.Representation3D));
  + for (const repr of reprs) this.applySelectMark(repr.transform.ref, true);
  }
  });
  }
  