return (bits + 31) & ~31;
  }

  /**
   * Returns a hash function which computes its hash code by concatenating the hash codes of the
   * underlying hash functions together. This can be useful if you need to generate hash codes of a
   * specific length.
   *
   * <p>For example, if you need 1024-bit hash codes, you could join two {@link Hashing#sha512} hash

 * amortized) constant time operations. Expected in the hashtable sense (depends on the hash
 * function doing a good job of distributing the elements to the buckets to a distribution not far
 * from uniform), and amortized since some operations can trigger a hash table resize.
 *
 * <p>As compared with {@link java.util.LinkedHashMap}, this structure places significantly reduced

   * objects per entry.  Instead we use an open-addressed hash table.  This design is basically
   * equivalent to RegularImmutableSet, save that instead of having a hash table containing the
   * elements directly and null for empty positions, we store indices of the keys in the hash table,
   * and ABSENT for empty positions.  We then look up the keys in alternatingKeysAndValues.
   *

        return this.getCount() == that.getCount()
            && Objects.equal(this.getElement(), that.getElement());
      }
      return false;
    }

    /**
     * Return this entry's hash code, following the behavior specified in {@link
     * Multiset.Entry#hashCode}.
     */
    @Override
    public int hashCode() {
      E e = getElement();

    Set<Set<Integer>> reverse = powerSet(ImmutableSet.copyOf(elements.asList().reverse()));
    new EqualsTester().addEqualityGroup(forward, reverse).testEquals();
  }

  /**
   * Test that a hash code miscomputed by "input.hashCode() * tooFarValue / 2" is correct under our
   * {@code hashCode} implementation.
   */
  public void testPowerSetHashCode_inputHashCodeTimesTooFarValueIsZero() {

    if (key == null) {
      return null;
    }
    int hash = hash(key);
    return segmentFor(hash).getEntry(key, hash);
  }

  @Override
  public boolean containsKey(@CheckForNull Object key) {
    if (key == null) {
      return false;
    }
    int hash = hash(key);
    return segmentFor(hash).containsKey(key, hash);
  }

  @Override

  public void testCreateFromHashMultimap() {
    Multimap<Double, Double> hash = HashMultimap.create();
    hash.put(1.0, 2.0);
    hash.put(2.0, 3.0);
    hash.put(3.0, 4.0);
    hash.put(4.0, 5.0);

    TreeMultimap<Double, Double> copyFromHash = TreeMultimap.create(hash);
    assertEquals(hash, copyFromHash);
    assertEquals(Ordering.natural(), copyFromHash.keyComparator());

        adjust = ~~adjust;
        // in GWT, we have to deal with integer overflow carefully
      }
      int hash = 1;
      for (Set<E> axis : axes) {
        hash = 31 * hash + (size() / axis.size() * axis.hashCode());

        hash = ~~hash;
      }
      hash += adjust;
      return ~~hash;
    }
  }

  /**
   * Returns the set of all possible subsets of {@code set}. For example, {@code

    assertNull(segment.get(key, hash));

    // count == 0
    table.set(index, entry);
    assertNull(segment.get(key, hash));
    assertFalse(segment.containsKey(key, hash));
    assertFalse(segment.containsValue(value));

    // count == 1
    segment.count++;
    assertSame(value, segment.get(key, hash));
    assertTrue(segment.containsKey(key, hash));
    assertTrue(segment.containsValue(value));

    assertNull(segment.get(key, hash));

    // count == 0
    table.set(index, entry);
    assertNull(segment.get(key, hash));
    assertFalse(segment.containsKey(key, hash));
    assertFalse(segment.containsValue(value));

    // count == 1
    segment.count++;
    assertSame(value, segment.get(key, hash));
    assertTrue(segment.containsKey(key, hash));
    assertTrue(segment.containsValue(value));