public void testToArray_withNull() {
    List<@Nullable Double> list = Arrays.asList(0.0, 1.0, null);
    assertThrows(NullPointerException.class, () -> Doubles.toArray(list));
  }

  public void testToArray_withConversion() {
    double[] array = {0.0, 1.0, 2.0};

    List<Byte> bytes = Arrays.asList((byte) 0, (byte) 1, (byte) 2);
    List<Short> shorts = Arrays.asList((short) 0, (short) 1, (short) 2);

  public void testToArray_withNull() {
    List<@Nullable Integer> list = Arrays.asList((int) 0, (int) 1, null);
    assertThrows(NullPointerException.class, () -> Ints.toArray(list));
  }

  public void testToArray_withConversion() {
    int[] array = {0, 1, 2};

    List<Byte> bytes = Arrays.asList((byte) 0, (byte) 1, (byte) 2);
    List<Short> shorts = Arrays.asList((short) 0, (short) 1, (short) 2);

  public void testToArray_withNull() {
    List<@Nullable Short> list = Arrays.asList((short) 0, (short) 1, null);
    assertThrows(NullPointerException.class, () -> Shorts.toArray(list));
  }

  public void testToArray_withConversion() {
    short[] array = {(short) 0, (short) 1, (short) 2};

    List<Byte> bytes = Arrays.asList((byte) 0, (byte) 1, (byte) 2);
    List<Short> shorts = Arrays.asList((short) 0, (short) 1, (short) 2);