return cancellationDelegate = new SupplantableFuture(lock, submitToExecutor(schedule));
        }
        if (!cancellationDelegate.currentFuture.isCancelled()) {
          cancellationDelegate.currentFuture = submitToExecutor(schedule);
        }
        return cancellationDelegate;
      }

      private ScheduledFuture<@Nullable Void> submitToExecutor(Schedule schedule) {