* (AbstractFutureState class initialization can log, and that logging could in theory call into
   * AbstractFuture, which wouldn't yet have had the chance to perform any class initialization of
   * its own.)
   */

  /** A special value to represent {@code null}. */
  static final Object NULL = new Object();

  /*
   * Despite declaring this field in AbstractFutureState, we still use the logger for

 * </ul>
 *
 * <h3>Implementations</h3>
 *
 * <ul>
 *   <li>{@link ImmutableListMultimap}
 *   <li>{@link ImmutableSetMultimap}
 *   <li>Configure your own mutable multimap with {@link MultimapBuilder}
 *   <li>{@link LinkedListMultimap} (for one unusual kind of mutable {@code Multimap})
 * </ul>
 *

     *
     * In theory, we can quickly determine the size of any Collection. However, thanks to
     * regrettable implementations like our own Sets.filter, Collection.size() is sometimes a
     * linear-time operation, and it can even have side effects. Thus, we limit the special case to

import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Generated tests for {@link Monitor}.
 *
 * <p>This test class generates all of its own test cases in the {@link #suite()} method. Every
 * {@code enterXxx}, {@code tryEnterXxx}, and {@code waitForXxx} method of the {@code Monitor} class

 * href="https://github.com/lukas-krecan/future-converter">Future Converter</a>.)
 *
 * <h3>Extension</h3>
 *
 * If you want a class like {@code FluentFuture} but with extra methods, we recommend declaring your
 * own subclass of {@link ListenableFuture}, complete with a method like {@link #from} to adapt an
 * existing {@code ListenableFuture}, implemented atop a {@link ForwardingListenableFuture} that

///

* If the PR can be simplified in a way, you can ask for that, but there's no need to be too picky, there might be a lot of subjective points of view (and I will have my own as well 🙈), so it's better if you can focus on the fundamental things.

### Tests { #tests }

* Help me check that the PR has **tests**.

* Check that the tests **fail** before the PR. 🚨

### Generic types with type parameters { #generic-types-with-type-parameters }

There are some data structures that can contain other values, like `dict`, `list`, `set` and `tuple`. And the internal values can have their own type too.

These types that have internal types are called "**generic**" types. And it's possible to declare them, even with their internal types.

 *
 * ## OkHttpClients Should Be Shared
 *
 * OkHttp performs best when you create a single `OkHttpClient` instance and reuse it for all of
 * your HTTP calls. This is because each client holds its own connection pool and thread pools.
 * Reusing connections and threads reduces latency and saves memory. Conversely, creating a client
 * for each request wastes resources on idle pools.
 *

      // before the cancelled future completes, it will synchronously complete both the newFuture
      // from the cancelled operation and its own. This can cause one runnable to queue two tasks,
      // breaking the invariant this method relies on to iteratively run the next task after the
      // previous one completes.
      if (get() == RunningState.CANCELLED) {

    size = 0;
    modCount++;
  }

  // Views

  /**
   * {@inheritDoc}
   *
   * <p>If the multimap is modified while an iteration over the list is in progress (except through
   * the iterator's own {@code add}, {@code set} or {@code remove} operations) the results of the
   * iteration are undefined.
   *
   * <p>The returned list is not serializable and does not have random access.
   */
  @Override