@Test
  public void deleteOneTest() {
    final int n = 1_000;
    IntArray arr = IntArray.empty();
    for(int k = 0; k < n; k++) {
      for(int i = 0; i < k; i++) {
        final IntArray arr2 = arr.remove(i);
        final Iterator<Integer> iter = arr2.iterator();
        for(int j = 0; j < k - 1; j++) {
          assertTrue(iter.hasNext());
          assertEquals(j < i ? j : j + 1, iter.next().intValue());
        }
        assertFalse(iter.hasNext());
      }
      arr = arr.snoc(k);
      assertEquals(k + 1, arr.size());
      assertEquals(k, arr.last().intValue());
    }
  }