for (int i = 0; i < perm.size(); i++) {
        MinMaxPriorityQueue<Integer> q = MinMaxPriorityQueue.create(perm);
        q.removeAt(i);
        assertIntactUsingStartedWith(perm, q);
      }
    }
  }

  /** Regression test for bug found. */
  public void testCorrectOrdering_regression() {