reset method
void
reset()
Full reset: zeros length and releases the order buffer, the reverse-index buffer, the subtree-size cache buffer back to empty, and clears roots in place (preserving the stable list reference). Used on controller-wide clear.
Implementation
void reset() {
_len = 0;
_orderNids = Int32List(0);
_indexByNid = Int32List(0);
_subtreeSizeByNid = Int32List(0);
roots.clear();
_onMutated();
}