}

    @Override
    public @Nullable Object[] toArray() {
      // creating an ArrayList so filtering happens once
      return Lists.newArrayList(iterator()).toArray();
    }

    @Override
    @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
    public <T extends @Nullable Object> T[] toArray(T[] array) {
      return Lists.newArrayList(iterator()).toArray(array);