* value and the old value.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *
 * <p>The lists returned by {@link #get}, {@link #removeAll}, and {@link #replaceValues} all
 * implement {@link java.util.RandomAccess}.
 *

    server.requestClientAuth()
    server.enqueue(
      MockResponse
        .Builder()
        .body("abc")
        .build(),
    )
    val call = client.newCall(Request.Builder().url(server.url("/")).build())
    val response = call.execute()
    assertThat(response.handshake!!.peerPrincipal)
      .isEqualTo(X500Principal("CN=Local Host"))
    assertThat(response.handshake!!.localPrincipal)

 *   <li>enqueuing weak references to unreachable referents in their reference queue
 * </ul>
 *
 * <p>This class uses (possibly repeated) invocations of {@link java.lang.System#gc()} to cause
 * finalization to happen. However, a call to {@code System.gc()} is specified to be no more than a
 * hint, so this technique may fail at the whim of the JDK implementation, for example if a user

     * we must return it in the following next() call even if it was in the process of being removed
     * when hasNext() was called.
     */
    private @Nullable E nextItem;

    /**
     * Index of element returned by most recent call to next. Reset to -1 if this element is deleted
     * by a call to remove.
     */
    private int lastRet;

    Itr() {
      lastRet = -1;

    }
  }

  /**
   * Returns an unmodifiable <b>view</b> of the union of two sets. The returned set contains all
   * elements that are contained in either backing set. Iterating over the returned set iterates
   * first over all the elements of {@code set1}, then over each element of {@code set2}, in order,
   * that is not contained in {@code set1}.
   *

        existingCounter = countMap.putIfAbsent(element, new AtomicInteger(occurrences));
        if (existingCounter == null) {
          return 0;
        }
        // existingCounter != null: fall through to operate against the existing AtomicInteger
      }

      while (true) {
        int oldValue = existingCounter.get();
        if (oldValue != 0) {
          try {

   * entire stream. To avoid a potentially expensive operation, see {@link #lengthIfKnown}.
   *
   * <p>The default implementation calls {@link #lengthIfKnown} and returns the value if present. If
   * absent, it will fall back to a heavyweight operation that will open a stream, {@link
   * Reader#skip(long) skip} to the end of the stream, and return the total number of chars that
   * were skipped.
   *

        | ((source[offset + 3] & 0xFF) << 24);
  }

  /**
   * Indicates that the load and store operations will be very efficient because of use of VarHandle
   * or Unsafe. May be useful for calling code to fall back on an alternative implementation that is
   * slower than those implementations but faster than the pure-Java mask-and-shift.
   */
  static boolean usingFastPath() {
    return byteArray.usesFastPath();
  }

  /**
   * Returns an instance of {@code interfaceType} that delegates all method calls to the {@code
   * target} object, enforcing the specified time limit on each call. This time-limited delegation
   * is also performed for calls to {@link Object#equals}, {@link Object#hashCode}, and {@link
   * Object#toString}.
   *
   * <p>If the target method call finishes before the limit is reached, the return value or

   * {@link MoreExecutors#directExecutor}. Normally, when the first future completes, all the other
   * tasks would be called recursively. Here, we detect that the delegate executor is executing
   * inline, and maintain a queue to dispatch tasks iteratively. There is one instance of this class
   * per call to submit() or submitAsync(), and each instance supports only one call to execute().
   *