int newVersion = currentVersion + 1;

            // Derive new key from current key
            String rotationLabel = String.format("KeyRotation-v%d", newVersion);
            byte[] newKey = deriveKey(currentKey, rotationLabel, String.valueOf(System.currentTimeMillis()).getBytes(), currentKey.length);

            // Archive old key (keep last version for rollback)

 * default} methods. Specifically, it forwards calls only for methods that existed <a
 * href="https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ConcurrentMap.html">before
 * {@code default} methods were introduced</a>. For newer methods, like {@code forEach}, it inherits
 * their default implementations. When those implementations invoke methods, they invoke methods on
 * the {@code ForwardingConcurrentMap}.
 *
 * @author Charles Fry
 * @since 2.0

 * are provided.
 * <p>
 * The jCIFS client maps DOS error codes to NTSTATUS codes. This means that
 * the user may recieve a different error from a legacy server than that of
 * a newer varient such as Windows NT and above. If you should encounter
 * such a case, please report it to jcifs at samba dot org and we will
 * change the mapping.
 */

 * bugs in OpenJDK 6 or higher.
 *
 * @author Kevin Bourrillion
 */
// TODO(cpovirk): consider renaming this class in light of our now running it under newer JDKs.
@AndroidIncompatible // test-suite builders
public class OpenJdk6MapTests extends TestsForMapsInJavaUtil {
  public static Test suite() {
    return new OpenJdk6MapTests().allTests();
  }

  @Override

    should not use them for communication between trusted and untrusted code.

6.  For the mainline flavor, we test the libraries using OpenJDK 8, 11, and 17
    on Linux, with some additional testing on newer JDKs and on Windows. Some
    features, especially in `com.google.common.io`, may not work correctly in
    non-Linux environments. For the Android flavor, our unit tests also run on
    API level 23 (Marshmallow).

        int newTableIndex = hash & newMask;
        int newNext = CompactHashing.tableGet(newTable, newTableIndex);
        CompactHashing.tableSet(newTable, newTableIndex, oldNext);
        entries[entryIndex] = CompactHashing.maskCombine(hash, newNext, newMask);

        oldNext = CompactHashing.getNext(oldEntry, oldMask);
      }
    }

    this.table = newTable;

Some requests will have a cached response. When this cached response isn’t fresh, OkHttp can do a _conditional GET_ to download an updated response if it’s newer than what’s cached. This requires headers like `If-Modified-Since` and `If-None-Match` to be added.

## Rewriting Responses

R8 / ProGuard
-------------

R8 and ProGuard are both code optimizers for `.class` files.

R8 is the [default optimizer][r8] in Android Studio 3.4 and newer. It works well with all
releases of OkHttp.

ProGuard was the previous default. We’re [tracking problems][proguard_problems] with interactions

 * as a single request/response exchange.
 *
 * ## Modern TLS
 *
 * There are trade-offs when selecting which options to include when negotiating a secure connection
 * to a remote host. Newer TLS options are quite useful:
 *
 *  * Server Name Indication (SNI) enables one IP address to negotiate secure connections for
 *    multiple domain names.
 *

      if (existing != null) {
        return existing;
      }
      L created = supplier.get();
      ArrayReference<L> newRef = new ArrayReference<>(created, index, queue);
      while (!locks.compareAndSet(index, existingRef, newRef)) {
        // we raced, we need to re-read and try again
        existingRef = locks.get(index);
        existing = existingRef == null ? null : existingRef.get();