// nulls are usually out of bounds for a subset, so ban them altogether
      for (Object o : elements) {
        if (o == null) {
          throw new NullPointerException();
        }
      }

      // prepare extreme values to be filtered out of view
      E firstExclusive = delegate.belowSamplesGreater();
      E lastExclusive = delegate.aboveSamplesLesser();
      if (from != Bound.NO_BOUND) {

      // nulls are usually out of bounds for a subset, so ban them altogether
      for (Object o : elements) {
        if (o == null) {
          throw new NullPointerException();
        }
      }

      // prepare extreme values to be filtered out of view
      E firstExclusive = delegate.belowSamplesGreater();
      E lastExclusive = delegate.aboveSamplesLesser();
      if (from != Bound.NO_BOUND) {