public static <T, U extends T> U findInstance(@NotNull Iterator<? extends T> iterator, @NotNull Class<? extends U> aClass) {
    //noinspection unchecked
    return (U)find(iterator, FilteringIterator.instanceOf(aClass));
  }
public static <T, U extends T> U findInstance(@NotNull Iterator<? extends T> iterator, @NotNull Class<? extends U> aClass)