code: function removeChildren(node) {
      node = node.lastChild;
      while (node) {
        var next = node.previousSibling;
        recollectNodeTree(node, true);
        node = next;
      }
    }
docs: Recollect/unmount all children.
  - we use .lastChild here because it causes less reflow than .firstChild
  - it's also cheaper than accessing the .childNodes Live NodeList