import com.google.common.annotations.GwtCompatible;
import com.google.j2objc.annotations.WeakOuter;
import java.util.concurrent.Callable;
import java.util.concurrent.RunnableFuture;
import org.jspecify.annotations.Nullable;

/**
 * A {@link RunnableFuture} that also implements the {@link ListenableFuture} interface.
 *
 * <p>This should be used in preference to {@link ListenableFutureTask} when possible for
 * performance reasons.