*/
  @SuppressWarnings("unchecked") // ImmediateCancelledFuture can work with any type
  public static <V extends @Nullable Object> ListenableFuture<V> immediateCancelledFuture() {
    ListenableFuture<Object> instance = ImmediateCancelledFuture.INSTANCE;
    if (instance != null) {
      return (ListenableFuture<V>) instance;
    }
    return new ImmediateCancelledFuture<>();
  }

  /**

import static com.google.common.truth.Truth.assertWithMessage;
import static com.google.common.util.concurrent.ClosingFuture.withoutCloser;
import static com.google.common.util.concurrent.Futures.immediateCancelledFuture;
import static com.google.common.util.concurrent.Futures.immediateFailedFuture;
import static com.google.common.util.concurrent.Futures.immediateFuture;