*       Future} is "completed" even if it is cancelled while its underlying work continues on a
 *       thread, an RPC, etc. The {@code Future} is also "completed" if it fails "early" -- for
 *       example, if the deadline expires on a {@code Future} returned from {@link
 *       Futures#withTimeout} while the {@code Future} it wraps continues its underlying work. So

      MockExecutor mock = new MockExecutor();
      TestExecutor testExecutor = new TestExecutor(mock);
      Future<?> f = testExecutor.submit(doNothing());
      mock.assertLastMethodCalled("submit");
      f.get();
    }
    {
      MockExecutor mock = new MockExecutor();
      TestExecutor testExecutor = new TestExecutor(mock);
      Future<String> f = testExecutor.submit(doNothing(), RESULT_VALUE);
      mock.assertLastMethodCalled("submit");

    UncheckedThrowingFuture<V> future = new UncheckedThrowingFuture<V>();
    future.complete(checkNotNull(error));
    return future;
  }

  public static <V> ListenableFuture<V> throwingRuntimeException(RuntimeException e) {
    UncheckedThrowingFuture<V> future = new UncheckedThrowingFuture<V>();
    future.complete(checkNotNull(e));
    return future;
  }

	OnComplete(cb func(try Try[T]), ctx ...Executor)
	IsCompleted() bool
	//	Value() Option[Try[T]]
	Failed() Future[error]
	Recover(f func(err error) T, ctx ...Executor) Future[T]
	RecoverWith(f func(err error) Future[T], ctx ...Executor) Future[T]
}

type Try[T any] struct {
	v   *T
	err error
}

func (r Try[T]) IsSuccess() bool {
	return r.v != nil
}

type ByteBuffer struct {
	pos       int
	buf       []byte

  public void testScheduleRunnable() throws Exception {
    Runnable command = () -> {};

    ListenableScheduledFuture<?> future = executorService.schedule(command, Duration.ofSeconds(12));

    assertThat(future.get()).isEqualTo("schedule");
    assertThat(recordedCommand).isSameInstanceAs(command);
    assertThat(recordedTimeUnit).isEqualTo(TimeUnit.NANOSECONDS);

import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.RejectedExecutionException;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link Future} that accepts completion listeners. Each listener has an associated executor, and
 * it is invoked using this executor once the future's computation is {@linkplain Future#isDone()

import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.RejectedExecutionException;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link Future} that accepts completion listeners. Each listener has an associated executor, and
 * it is invoked using this executor once the future's computation is {@linkplain Future#isDone()

# the go.mod file to record a specific, stable toolchain version that can.

! go mod verify
stderr '^go: rsc.io/future@v1.0.0: module rsc.io/future@v1.0.0 requires go >= 1.999 \(running go 1.21.0\)'

! go mod graph
stderr '^go: rsc.io/future@v1.0.0: module rsc.io/future@v1.0.0 requires go >= 1.999 \(running go 1.21.0\)'

# TODO(#64008): 'go mod download' without arguments should fail too.

@ElementTypesAreNonnullByDefault
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.
   *
   * <p>If the future's {@link Future#get() get} method throws an {@link ExecutionException}, then

            projectBuildFutureTask.run();
        }
        return projectBuildFutureTask;
    }

    public Future<ProjectSegment> take() throws InterruptedException {
        return null;
    }

    public Future<ProjectSegment> poll() {
        return null;
    }

    public Future<ProjectSegment> poll(long timeout, TimeUnit unit) throws InterruptedException {
        return null;
    }