@GwtIncompatible // Thread
  private void testSupplierThreadSafe(Function<Supplier<Boolean>, Supplier<Boolean>> memoizer)
      throws Throwable {
    AtomicInteger count = new AtomicInteger(0);
    AtomicReference<Throwable> thrown = new AtomicReference<>(null);
    int numThreads = 3;
    Thread[] threads = new Thread[numThreads];
    long timeout = SECONDS.toNanos(60);

    Supplier<Boolean> supplier =
        new Supplier<Boolean>() {

                + size // for the get threads,
                + 1); // for the main thread
    ExecutorService executor = newFixedThreadPool(barrier.getParties());
    AtomicReference<AbstractFuture<String>> currentFuture = Atomics.newReference();
    AtomicReference<AbstractFuture<String>> setFutureFuture = Atomics.newReference();
    AtomicBoolean setFutureSetSuccess = new AtomicBoolean();

    return new ExecutionSequencer();
  }

  /** This reference acts as a pointer tracking the head of a linked list of ListenableFutures. */
  private final AtomicReference<ListenableFuture<@Nullable Void>> ref =
      new AtomicReference<>(immediateVoidFuture());

  @LazyInit private ThreadConfinedTaskQueue latestTaskQueue = new ThreadConfinedTaskQueue();

  /**

              <!--              <exclude>org.apache.maven.model.resolution.ModelResolver#resolveModel(org.apache.maven.api.model.Dependency,java.util.concurrent.atomic.AtomicReference):METHOD_NEW_DEFAULT</exclude>-->

    return new ExecutionSequencer();
  }

  /** This reference acts as a pointer tracking the head of a linked list of ListenableFutures. */
  private final AtomicReference<ListenableFuture<@Nullable Void>> ref =
      new AtomicReference<>(immediateVoidFuture());

  @LazyInit private ThreadConfinedTaskQueue latestTaskQueue = new ThreadConfinedTaskQueue();

  /**

    return (type instanceof Class) ? ((Class<?>) type).getName() : type.toString();
  }

  static @Nullable Type getComponentType(Type type) {
    checkNotNull(type);
    AtomicReference<@Nullable Type> result = new AtomicReference<>();
    new TypeVisitor() {
      @Override
      void visitTypeVariable(TypeVariable<?> t) {
        result.set(subtypeOfComponentType(t.getBounds()));
      }

      @Override

import java.net.Proxy
import java.security.cert.X509Certificate
import java.util.Arrays
import java.util.concurrent.CountDownLatch
import java.util.concurrent.atomic.AtomicInteger
import java.util.concurrent.atomic.AtomicReference
import javax.net.ssl.HostnameVerifier
import javax.net.ssl.SSLPeerUnverifiedException
import javax.net.ssl.SSLSession
import javax.net.ssl.X509TrustManager
import kotlin.test.assertFailsWith

                + size // for the get threads,
                + 1); // for the main thread
    ExecutorService executor = newFixedThreadPool(barrier.getParties());
    AtomicReference<AbstractFuture<String>> currentFuture = Atomics.newReference();
    AtomicReference<AbstractFuture<String>> setFutureFuture = Atomics.newReference();
    AtomicBoolean setFutureSetSuccess = new AtomicBoolean();

 */
@GwtCompatible
@IgnoreJRERequirement // Users will use this only if they're already using streams.
public final class MoreCollectors {

  /*
   * TODO(lowasser): figure out if we can convert this to a concurrent AtomicReference-based
   * collector without breaking j2cl?
   */
  private static final Collector<Object, ?, Optional<Object>> TO_OPTIONAL =
      Collector.of(
          ToOptionalState::new,
          ToOptionalState::add,

    return (type instanceof Class) ? ((Class<?>) type).getName() : type.toString();
  }

  static @Nullable Type getComponentType(Type type) {
    checkNotNull(type);
    AtomicReference<@Nullable Type> result = new AtomicReference<>();
    new TypeVisitor() {
      @Override
      void visitTypeVariable(TypeVariable<?> t) {
        result.set(subtypeOfComponentType(t.getBounds()));
      }

      @Override