public static @NotNull <T> Meta<T> create(Function<? super T, ? extends Iterable<? extends T>> tree) {
      return new Meta<>(JBIterable.empty(), TreeTraversal.PRE_ORDER_DFS,
                        tree, Cond.TRUE, Cond.TRUE, Cond.TRUE, Cond.FALSE, Cond.FALSE, Cond.FALSE,
                        Functions.id(), null);
    }
public static @NotNull <T> Meta<T> create(Function<? super T, ? extends Iterable<? extends T>> tree)