@Override
public ITreeCursor openCursor() {
if (openCursors == null) {
openCursors = new ArrayList<>(4);
}
final ITreeCursorMutable result =
new TreeCursorMutable(this, new PatriciaTraverser(this, root), root.hasValue());
openCursors.add(result);
return result;
}
@Override
public void cursorClosed(@NotNull ITreeCursorMutable cursor) {
openCursors.remove(cursor);
}