/**
   * This classloader disallows {@link java.lang.invoke.VarHandle}, which will prevent us from
   * selecting the {@code VarHandleAtomicHelper} strategy.
   */
  private static final ClassLoader NO_VAR_HANDLE =
      getClassLoader(ImmutableSet.of("java.lang.invoke.VarHandle"));

  /**
   * This classloader disallows {@link java.lang.invoke.VarHandle} and {@link sun.misc.Unsafe},

 *
 * @author Anthony Zana
 * @since 10.0
 */
@GwtCompatible
public interface FutureCallback<V extends @Nullable Object> {
  /** Invoked with the result of the {@code Future} computation when it is successful. */
  void onSuccess(@ParametricNullness V result);

  /**
   * Invoked when a {@code Future} computation fails or is canceled.
   *

          AlpnProvider(names),
        )
      putMethod.invoke(null, sslSocket, alpnProvider)
    } catch (e: InvocationTargetException) {
      throw AssertionError("failed to set ALPN", e)
    } catch (e: IllegalAccessException) {
      throw AssertionError("failed to set ALPN", e)
    }
  }

  override fun afterHandshake(sslSocket: SSLSocket) {
    try {
      removeMethod.invoke(null, sslSocket)
    } catch (e: IllegalAccessException) {

 */

package com.google.common.util.concurrent;

import com.google.common.annotations.GwtCompatible;
import java.util.concurrent.Executor;

/**
 * An {@link Executor} that runs each task in the thread that invokes {@link Executor#execute
 * execute}.
 */
@GwtCompatible
enum DirectExecutor implements Executor {
  INSTANCE;

  @Override
  public void execute(Runnable command) {
    command.run();
  }

import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import org.jspecify.annotations.Nullable;

/**
 * Soft reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import org.jspecify.annotations.Nullable;

/**
 * Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import org.jspecify.annotations.Nullable;

/**
 * Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

                return 0;
              case 1:
                return 1;
              case 2:
                return endOfData();
              default:
                throw new AssertionError("Should not have been invoked again");
            }
          }
        };

    assertTrue(iter.hasNext());
    assertEquals(0, (int) iter.next());

    // verify idempotence of hasNext()
    assertTrue(iter.hasNext());

@J2ktIncompatible
@GwtIncompatible
public interface FinalizableReference {
  /**
   * Invoked on a background thread after the referent has been garbage collected unless security
   * restrictions prevented starting a background thread, in which case this method is invoked when
   * new references are created.
   */
  void finalizeReferent();

  protected AbstractExecutionThreadService() {}

  /**
   * Start the service. This method is invoked on the execution thread.
   *
   * <p>By default this method does nothing.
   */
  protected void startUp() throws Exception {}

  /**
   * Run the service. This method is invoked on the execution thread. Implementations must respond
   * to stop requests. You could poll for lifecycle changes in a work loop: