Author: Klaus Post <******@****.***>
Date:   Thu Nov 18 12:15:22 2021 -0800

    Improve performance on multiple versions (#13573)
```

- A fix must be a valid fix that was reproduced and seen in a customer environment, for example.

```
commit 886262e58af77ebc7c836ef587c08544e9a0c271
Author: Harshavardhana <******@****.***>
Date:   Wed Nov 17 15:49:12 2021 -0800

    final Map<C, V> seen = factory.get();
    final Iterator<Map<C, V>> mapIterator = backingMap.values().iterator();
    Iterator<Entry<C, V>> entryIterator = emptyIterator();

    @Override
    protected @Nullable C computeNext() {
      while (true) {
        if (entryIterator.hasNext()) {
          Entry<C, V> entry = entryIterator.next();
          if (!seen.containsKey(entry.getKey())) {

            });

    // Don't copy this into your own test!
    // Use e.g. awaitClear or await(CountDownLatch) instead.
    GcFinalization.awaitFullGc();

    // Attempt to help with some flakiness that we've seen: b/387521512.
    GcFinalization.awaitFullGc();

    assertEquals(0, finalizerRan.getCount());
    assertNull(ref.get());
  }

 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public

 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public

// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License

// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License

 * </ul>
 *
 * <p>If you do chain your operations manually, you may want to use {@link FluentFuture}.
 *
 * @author Kevin Bourrillion
 * @author Nishant Thakkar
 * @author Sven Mawson
 * @since 1.0
 */
@GwtCompatible
public final class Futures extends GwtFuturesCatchingSpecialization {

  // A note on memory visibility.

    31622776601683L,
    316227766016837L,
    3162277660168379L,
    31622776601683793L,
    316227766016837933L,
    3162277660168379331L
  };

  /**
   * Returns {@code b} to the {@code k}th power. Even if the result overflows, it will be equal to
   * {@code BigInteger.valueOf(b).pow(k).longValue()}. This implementation runs in {@code O(log k)}
   * time.
   *
   * @throws IllegalArgumentException if {@code k < 0}
   */

   * HTTPS.
   */
  fun handshake(): Handshake?

  /**
   * Returns the protocol negotiated by this connection, or [Protocol.HTTP_1_1] if no protocol
   * has been negotiated. This method returns [Protocol.HTTP_1_1] even if the remote peer is using
   * [Protocol.HTTP_1_0].
   */
  fun protocol(): Protocol