throw new AssertionError("Should never get here.");
      }
      h1 ^= mixK1(k1);
      h2 ^= mixK2(k2);
    }

    @Override
    protected HashCode makeHash() {
      h1 ^= length;
      h2 ^= length;

      h1 += h2;
      h2 += h1;

      h1 = fmix64(h1);
      h2 = fmix64(h2);

      h1 += h2;
      h2 += h1;

      return HashCode.fromBytesNoCopy(