/**
   * Applies a supplemental hash function to a given hash code, which defends against poor quality
   * hash functions. This is critical when the concurrent hash map uses power-of-two length hash
   * tables, that otherwise encounter collisions for hash codes that do not differ in lower or upper
   * bits.
   *
   * @param h hash code
   */
  static int rehash(int h) {
    // Spread bits to regularize both segment and index locations,

    public E higher(E e) {
      synchronized (mutex) {
        return delegate().higher(e);
      }
    }

    @Override
    @CheckForNull
    public E lower(E e) {
      synchronized (mutex) {
        return delegate().lower(e);
      }
    }

    @Override
    @CheckForNull
    public E pollFirst() {
      synchronized (mutex) {
        return delegate().pollFirst();

    assertSame(testEquivalence, map.valueEquivalence);
    assertSame(map.keyStrength.defaultEquivalence(), map.keyEquivalence);
  }

  public void testSetConcurrencyLevel() {
    // round up to the nearest power of two

    checkConcurrencyLevel(1, 1);
    checkConcurrencyLevel(2, 2);
    checkConcurrencyLevel(3, 4);
    checkConcurrencyLevel(4, 4);
    checkConcurrencyLevel(5, 8);
    checkConcurrencyLevel(6, 8);

    assertSame(testEquivalence, map.valueEquivalence);
    assertSame(map.keyStrength.defaultEquivalence(), map.keyEquivalence);
  }

  public void testSetConcurrencyLevel() {
    // round up to the nearest power of two

    checkConcurrencyLevel(1, 1);
    checkConcurrencyLevel(2, 2);
    checkConcurrencyLevel(3, 4);
    checkConcurrencyLevel(4, 4);
    checkConcurrencyLevel(5, 8);
    checkConcurrencyLevel(6, 8);

    AssertionFailedError failure = new AssertionFailedError(message);
    failure.initCause(cause);
    return failure;
  }

  // This test covers a bug where an Error thrown from a callback could cause the TimeoutFuture to
  // never complete when timing out.  Notably, nothing would get logged since the Error would get

  static AtomicLong requests = new AtomicLong(0);
  static AtomicLong misses = new AtomicLong(0);

  @BeforeExperiment
  void setUp() {
    // random integers will be generated in this range, then raised to the
    // power of (1/concentration) and floor()ed
    max = Ints.checkedCast((long) Math.pow(distinctKeys, concentration));

    cache =
        CacheBuilder.newBuilder()
            .concurrencyLevel(segments)

 *
 * @author Louis Wasserman
 * @since 11.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class BigIntegerMath {
  /**
   * Returns the smallest power of two greater than or equal to {@code x}. This is equivalent to
   * {@code BigInteger.valueOf(2).pow(log2(x, CEILING))}.
   *
   * @throws IllegalArgumentException if {@code x <= 0}
   * @since 20.0
   */

  private static boolean shouldTrim(int actualUnique, int expectedUnique) {
    return actualUnique < (expectedUnique >> 1) + (expectedUnique >> 2);
  }

  // We use power-of-2 tables, and this is the highest int that's a power of 2
  static final int MAX_TABLE_SIZE = Ints.MAX_POWER_OF_TWO;

  // Represents how tightly we can pack things, as a maximum.
  private static final double DESIRED_LOAD_FACTOR = 0.7;

@GwtCompatible(emulated = true)
public class IntMathTest extends TestCase {
  public void testMaxSignedPowerOfTwo() {
    assertTrue(IntMath.isPowerOfTwo(IntMath.MAX_SIGNED_POWER_OF_TWO));

    // Extra work required to make GWT happy.
    long value = IntMath.MAX_SIGNED_POWER_OF_TWO * 2L;
    assertFalse(IntMath.isPowerOfTwo((int) value));
  }

  public void testCeilingPowerOfTwo() {
    for (int x : POSITIVE_INTEGER_CANDIDATES) {

   * (inclusive) to {@code upper} (inclusive). (These are the same values contained in {@code
   * Range.closed(lower, upper)}.)
   *
   * @throws IllegalArgumentException if {@code lower} is greater than {@code upper}
   * @since 23.0
   */
  public static ContiguousSet<Integer> closed(int lower, int upper) {
    return create(Range.closed(lower, upper), DiscreteDomain.integers());
  }