assertEquals(27, stats.evictionCount());
  }

  public void testMinus() {
    CacheStats one = new CacheStats(11, 13, 17, 19, 23, 27);
    CacheStats two = new CacheStats(53, 47, 43, 41, 37, 31);

    CacheStats diff = two.minus(one);
    assertEquals(76, diff.requestCount());
    assertEquals(42, diff.hitCount());
    assertEquals(42.0 / 76, diff.hitRate());
    assertEquals(34, diff.missCount());

  }

  private static long shiftMix(long val) {
    return val ^ (val >>> 47);
  }

  /** Implementation of Hash128to64 from util/hash/hash128to64.h */
  @VisibleForTesting
  static long hash128to64(long high, long low) {
    long a = (low ^ high) * K3;
    a ^= (a >>> 47);
    long b = (high ^ a) * K3;
    b ^= (b >>> 47);
    b *= K3;
    return b;
  }

  /**

    assertEquals(27, stats.evictionCount());
  }

  public void testMinus() {
    CacheStats one = new CacheStats(11, 13, 17, 19, 23, 27);
    CacheStats two = new CacheStats(53, 47, 43, 41, 37, 31);

    CacheStats diff = two.minus(one);
    assertEquals(76, diff.requestCount());
    assertEquals(42, diff.hitCount());
    assertEquals(42.0 / 76, diff.hitRate());
    assertEquals(34, diff.missCount());

    mmHeap.addAll(Lists.newArrayList(1, 2, 3, 4, 47, 1, 5, 3, 0));
    assertTrue("Heap is not intact initially", mmHeap.isIntact());
    assertEquals(9, mmHeap.size());
    mmHeap.remove(5);
    assertEquals(8, mmHeap.size());
    assertTrue("Heap is not intact after remove()", mmHeap.isIntact());
    assertEquals(47, (int) mmHeap.pollLast());
    assertEquals(4, (int) mmHeap.pollLast());

    }
  }

  private static long shiftMix(long val) {
    return val ^ (val >>> 47);
  }

  private static long hashLength16(long u, long v, long mul) {
    long a = (u ^ v) * mul;
    a ^= (a >>> 47);
    long b = (v ^ a) * mul;
    b ^= (b >>> 47);
    b *= mul;
    return b;
  }

  /**

    longValues.add(Integer.MAX_VALUE + 1L, Long.MAX_VALUE - 1L, Long.MAX_VALUE);

    // Now add values near 2^N for lots of values of N.
    for (int exponent : asList(32, 33, 39, 40, 41, 47, 48, 49, 55, 56, 57)) {
      long x = 1L << exponent;
      longValues.add(x, x + 1, x - 1);
    }
    longValues.add(194368031998L).add(194368031999L); // sqrt(2^75) rounded up and down

    longValues.add(Integer.MAX_VALUE + 1L, Long.MAX_VALUE - 1L, Long.MAX_VALUE);

    // Now add values near 2^N for lots of values of N.
    for (int exponent : asList(32, 33, 39, 40, 41, 47, 48, 49, 55, 56, 57)) {
      long x = 1L << exponent;
      longValues.add(x, x + 1, x - 1);
    }
    longValues.add(194368031998L).add(194368031999L); // sqrt(2^75) rounded up and down

    mmHeap.addAll(Lists.newArrayList(1, 2, 3, 4, 47, 1, 5, 3, 0));
    assertTrue("Heap is not intact initially", mmHeap.isIntact());
    assertEquals(9, mmHeap.size());
    mmHeap.remove(5);
    assertEquals(8, mmHeap.size());
    assertTrue("Heap is not intact after remove()", mmHeap.isIntact());
    assertEquals(47, (int) mmHeap.pollLast());
    assertEquals(4, (int) mmHeap.pollLast());

              | (1L << (29 - 2))
              | (1L << (31 - 2))
              | (1L << (37 - 2))
              | (1L << (41 - 2))
              | (1L << (43 - 2))
              | (1L << (47 - 2))
              | (1L << (53 - 2))
              | (1L << (59 - 2))
              | (1L << (61 - 2));
      // Look up n within the mask.
      return ((mask >> ((int) n - 2)) & 1) != 0;
    }

            32, 9, 10, 101, 97, 13, 105, 111, 110, 116, 114, 115, 108, 100, 99, 117, 109, 104, 112,
            103, 48, 46, 98, 49, 160, 102, 50, 118, 121, 107, 44, 119, 45, 58, 51, 53, 52, 57, 56,
            106, 54, 122, 55, 47, 41, 40, 124, 120, 1103, 1072, 1086, 113, 1080, 1575, 1077, 1085,
            1090, 12540, 1088, 12398, 95, 1089, 39, 1604, 33, 233, 12290, 30340, 1083, 1074, 12289,