message: Add missing `disassembleDOMTree()` function.
diff: @@ -287,3 +287,21 @@ export function findFixedPositionOffset(element: HTMLElement): { left: number, t
  }
  return { left: 0, top: 0 };
  }
  +
  +/**
  + * Disassemble all of the node below a DOM subtree
  + *
  + * This removes all the child nodes from every child and grandchild etc in
  + * the subtree.
  + *
  + * @param subtree The DOM tree to disassemble
  + */
  +export function disassembleDOMTree(subtree: ChildNode | ShadowRoot): void {
  + if (subtree == null) {
  + return;
  + }
  + for (const node of subtree.childNodes) {
  + disassembleDOMTree(node);
  + subtree.removeChild(node);
  + }
  +}
  