import java.util.Collection;
import java.util.EnumSet;
import java.util.Spliterator;
import java.util.function.Consumer;
import javax.annotation.CheckForNull;

/**
 * Implementation of {@link ImmutableSet} backed by a non-empty {@link java.util.EnumSet}.
 *
 * @author Jared Levy
 */
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // we're overriding default serialization

    // Lock while we check state. We must maintain the lock while adding the new pair so that
    // another thread can't run the list out from under us. We only add to the list if we have not
    // yet started execution.
    synchronized (this) {
      if (!executed) {
        runnables = new RunnableExecutorPair(runnable, executor, runnables);
        return;
      }
    }

    }
  }

  private static void assertIntactUsingStartedWith(
      Collection<?> startedWith, MinMaxPriorityQueue<?> q) {
    if (!q.isIntact()) {
      fail("Started with " + startedWith + ". State " + Arrays.toString(q.toArray()));
    }
  }

  private static void assertEqualsUsingSeed(
      long seed, @Nullable Object expected, @Nullable Object actual) {

    return new SingletonImmutableSet<>(element);
  }

  /*
   * TODO: b/315526394 - Skip the Builder entirely for the of(...) methods, since we don't need to
   * worry that we might trigger the fallback to the JDK-backed implementation? (The varargs one
   * _could_, so we could keep it as it is. Or we could convince ourselves that hash flooding is
   * unlikely in practice there, too.)
   */

  /**

   * tasks. Second, the returned list will always be empty, as any submitted task is considered to
   * have started execution. This applies also to tasks given to {@code invokeAll} or {@code
   * invokeAny} which are pending serial execution, even the subset of the tasks that have not yet
   * started execution. It is unclear from the {@code ExecutorService} specification if these should

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.HashMap;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Multiset implementation backed by a {@link HashMap}.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible(serializable = true, emulated = true)
@ElementTypesAreNonnullByDefault

      int expectedSize) {
    return new HashSet<>(Maps.capacity(expectedSize));
  }

  /**
   * Creates a thread-safe set backed by a hash map. The set is backed by a {@link
   * ConcurrentHashMap} instance, and thus carries the same concurrency guarantees.
   *
   * <p>Unlike {@code HashSet}, this class does NOT allow {@code null} to be used as an element. The

      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
    return added;
  }

  /**
   * Returns a synchronized (thread-safe) queue backed by the specified queue. In order to guarantee
   * serial access, it is critical that <b>all</b> access to the backing queue is accomplished
   * through the returned queue.
   *

    return CollectCollectors.<T, K, V, M>flatteningToMultimap(
        keyFunction, valueFunction, multimapSupplier);
  }

  /**
   * Creates a new {@code Multimap} backed by {@code map}, whose internal value collections are
   * generated by {@code factory}.
   *
   * <p><b>Warning: do not use</b> this method when the collections returned by {@code factory}

 *     Ordering.natural()
 *         .nullsFirst()
 *         .onResultOf(getBarFunction)
 *         .nullsLast();
 * }</pre>
 *
 * Note that each chaining method returns a new ordering instance which is backed by the previous
 * instance, but has the chance to act on values <i>before</i> handing off to that backing instance.
 * As a result, it usually helps to read chained ordering expressions <i>backwards</i>. For example,