@Test(timeout = TIMEOUT)
  public void testRadixSort() {
    int[] arrZero = new int[0];
    arrZero = Sorting.radixSort(arrZero);
    assertEquals(0, arrZero.length);
    int[] arrOne = new int[1];
    arrOne[0] = 4;
    arrOne = Sorting.radixSort(arrOne);
    assertEquals(1, arrOne.length);
    assertEquals(4, arrOne[0]);

    Random rand = new Random();
    for (int i = 0; i < 50; i++) {
      int arrlen = rand.nextInt(1000) + 2;
      int[] arrMany = new int[arrlen];
      int[] arrManySorted = new int[arrlen];
      for (int j = 0; j < arrlen; j++) {
        arrMany[j] = rand.nextInt(200) - 90;
      }
      System.arraycopy(arrMany, 0, arrManySorted, 0, arrlen);
      Arrays.sort(arrManySorted);
      arrMany = Sorting.radixSort(arrMany);
      assertArrayEquals(arrManySorted, arrMany);
    }
  }