*/
class TaskRunner(
  val backend: Backend,
  internal val logger: Logger = TaskRunner.logger,
) : Lockable {
  private var nextQueueName = 10000
  private var coordinatorWaiting = false
  private var coordinatorWakeUpAt = 0L

  /**
   * When we need a new thread to run tasks, we call [Backend.execute]. A few microseconds later we

      default:
        return new RegularImmutableAsList<E>(this, toArray());
    }
  }

  /** If this collection is backed by an array of its elements in insertion order, returns it. */
  Object @Nullable [] internalArray() {
    return null;
  }

  /**
   * If this collection is backed by an array of its elements in insertion order, returns the offset
   * where this collection's elements start.
   */

   * default initial capacity and load factor.
   */
  public static <B extends @Nullable Object> MutableClassToInstanceMap<B> create() {
    return new MutableClassToInstanceMap<>(new HashMap<Class<? extends @NonNull B>, B>());
  }

  /**
   * Returns a new {@code MutableClassToInstanceMap} instance backed by a given empty {@code

      other[size] = null;
    }
    copyIntoArray(other, 0);
    return other;
  }

  /** If this collection is backed by an array of its elements in insertion order, returns it. */
  @Nullable Object @Nullable [] internalArray() {
    return null;
  }

  /**
   * If this collection is backed by an array of its elements in insertion order, returns the offset
   * where this collection's elements start.
   */

      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

import com.google.common.annotations.J2ktIncompatible;
import com.google.common.annotations.VisibleForTesting;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableList} backed by a simple array.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class RegularImmutableList<E> extends ImmutableList<E> {

import java.util.Collection;
import java.util.EnumSet;
import java.util.Spliterator;
import java.util.function.Consumer;
import org.jspecify.annotations.Nullable;

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

import com.google.common.annotations.J2ktIncompatible;
import org.jspecify.annotations.Nullable;

/**
 * An {@link ImmutableAsList} implementation specialized for when the delegate collection is already
 * backed by an {@code ImmutableList} or array.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace, not default serialization

   */
  @Override
  Set<V> values();

  /**
   * Returns the inverse view of this bimap, which maps each of this bimap's values to its
   * associated key. The two bimaps are backed by the same data; any changes to one will appear in
   * the other.
   *
   * <p><b>Note:</b> There is no guaranteed correspondence between the iteration order of a bimap
   * and that of its inverse.
   *

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.HashMap;
import org.jspecify.annotations.Nullable;

/**
 * Multiset implementation backed by a {@link HashMap}.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible
public final class HashMultiset<E extends @Nullable Object> extends AbstractMapBasedMultiset<E> {