* {@link UnsupportedOperationException} when they are not implemented. Most implementations should
 * support either all add operations or none of them, all removal operations or none of them, and if
 * and only if all of these are supported, the {@code setCount} methods as well.
 *
 * <p>A multiset uses {@link Object#equals} to determine whether two instances should be considered

    }
    assertEquals(
        "multiset.size() should be the sum of the counts of all entries",
        size,
        getMultiset().size());
  }

  /** Call the {@code setCount()} method under test, and check its return value. */
  abstract void setCountCheckReturnValue(E element, int count);

  /**
   * Call the {@code setCount()} method under test, but do not check its return value. Callers

    val tags = EmptyTags
    val atomicTags = AtomicReference<Tags>(tags)
    val result =
      atomicTags.computeIfAbsent(String::class) {
        // 'Race' by making another computeIfAbsent call. In practice this would be another thread.
        assertThat(atomicTags.computeIfAbsent(Integer::class) { 5 as Integer }).isEqualTo(5)
        "a"
      }
    assertThat(result).isEqualTo("a")

   * @since 27.1
   */
  @CanIgnoreReturnValue
  boolean addEdge(EndpointPair<N> endpoints, E edge);

  /**
   * Removes {@code node} if it is present; all edges incident to {@code node} will also be removed.
   *
   * @return {@code true} if the network was modified as a result of this call
   */
  @CanIgnoreReturnValue
  boolean removeNode(N node);

  /**
   * Removes {@code edge} from this network, if it is present.
   *

 * **ExchangeFinder** chooses which connection carries each exchange. Where possible it will use the same connection for all exchanges in a single call. It prefers reusing pooled connections over establishing new connections.      

#### Per-Connection Locks

        assertThat(cache.asMap().containsKey(entry.getKey())).isTrue();
        assertThat(cache.asMap().containsValue(entry.getValue())).isTrue();
        // this getUnchecked() call shouldn't be a cache miss; verified below
        assertThat(cache.getUnchecked(entry.getKey())).isEqualTo(entry.getValue());
      }
      assertThat(cache.stats().missCount()).isEqualTo(WARMUP_SIZE);

   * occurs. The request triggering refresh will make a synchronous call to {@link
   * CacheLoader#reload}
   * to obtain a future of the new value. If the returned future is already complete, it is returned
   * immediately. Otherwise, the old value is returned.
   *
   * <p><b>Note:</b> <i>all exceptions thrown during refresh will be logged and then swallowed</i>.
   *

import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.Nullable;

/**
 * A TimeLimiter implementation which actually does not attempt to limit time at all. This may be
 * desirable to use in some unit tests. More importantly, attempting to debug a call which is
 * time-limited would be extremely annoying, so this gives you a time-limiter you can easily swap in
 * for your real time-limiter while you're debugging.
 *

    /** Do this task's work, and then start another, such as by calling [startNextTask]. */
    fun start()
  }

  private object TestThreadSerialTask : SerialTask {
    override fun start() = error("unexpected call")
  }

  inner class RunnableSerialTask(
    private val runnable: Runnable,
  ) : SerialTask {
    override fun start() {
      taskRunner.assertLockHeld()
      require(currentTask == this)

        threadPool.submit(
            new Callable<@Nullable Void>() {
              @Override
              public @Nullable Void call() throws InterruptedException {
                new Producer(q, 50).call();
                new Interrupter(mainThread).run();
                new Producer(q, 50).call();
                return null;
              }
            });
    List<Object> buf = new ArrayList<>();