List<Integer> one = Arrays.asList((int) 1);
    assertThat(Ints.toArray(one)).isEqualTo(ARRAY1);

    int[] array = {(int) 0, (int) 1, (int) 0xdeadbeef};

    List<Integer> three = Arrays.asList((int) 0, (int) 1, (int) 0xdeadbeef);
    assertThat(Ints.toArray(three)).isEqualTo(array);

    assertThat(Ints.toArray(Ints.asList(array))).isEqualTo(array);
  }

  public void testToArray_threadSafe() {