override fun completed(response: SimpleHttpResponse) {
  }

  override fun failed(ex: Exception) {
    println("Failed: $ex")
  }

  override fun cancelled() {
    println("Cancelled")
  }

 * A {@link ListenableFuture} whose result can be set by a {@link #set(Object)}, {@link
 * #setException(Throwable)} or {@link #setFuture(ListenableFuture)} call. It can also, like any
 * other {@code Future}, be {@linkplain #cancel cancelled}.
 *
 * <p>{@code SettableFuture} is the recommended {@code ListenableFuture} implementation when your
 * task cannot be implemented with {@link ListeningExecutorService}, the various {@link Futures}

      return;
    }

    /*
     * Any of the setException() calls below can fail if the output Future is cancelled between now
     * and then. This means that we're silently swallowing an exception -- maybe even an Error. But
     * this is no worse than what FutureTask does in that situation. Additionally, because the
     * Future was cancelled, its listeners have been run, so its consumers will not hang.
     *

    // stop it.
    blockingCallable.waitForStart();

    // This time, cancel the future for the first task. The task remains running, only the future
    // is cancelled.
    future1.cancel(false);

    // Give the second task a chance to (incorrectly) start up while the first task is running.
    // (This is the assertion that fails.)
    assertThat(future2.isDone()).isFalse();

  /**
   * Usually returns {@code null} but, if this {@code Future} has failed, may <i>optionally</i>
   * return the cause of the failure. "Failure" means specifically "completed with an exception"; it
   * does not include "was cancelled." To be explicit: If this method returns a non-null value,
   * then:
   *
   * <ul>
   *   <li>{@code isDone()} must return {@code true}
   *   <li>{@code isCancelled()} must return {@code false}

   * Usually returns {@code null} but, if the given {@code Future} has failed, may <i>optionally</i>
   * return the cause of the failure. "Failure" means specifically "completed with an exception"; it
   * does not include "was cancelled." To be explicit: If this method returns a non-null value,
   * then:
   *
   * <ul>
   *   <li>{@code isDone()} must return {@code true}
   *   <li>{@code isCancelled()} must return {@code false}

            } catch (final SmbException e) {
                if (e.getNtStatus() == 0xC0000120) {
                    // cancelled
                    log.debug("Request was cancelled", e);
                    return null;
                }
                throw e;
            }
            if (log.isTraceEnabled()) {

           * the lock) until after it's scheduled and the runningTask field is set.
           */
          if (requireNonNull(runningTask).isCancelled()) {
            // task may have been cancelled while blocked on the lock.
            return;
          }
          AbstractScheduledService.this.runOneIteration();
        } catch (Throwable t) {
          restoreInterruptIfIsInterruptedException(t);

 *
 * <p>Future that delegates to another but will finish early (via a {@link TimeoutException} wrapped
 * in an {@link ExecutionException}) if the specified duration expires. The delegate future is
 * interrupted and cancelled if it times out.
 */
@J2ktIncompatible
@GwtIncompatible
final class TimeoutFuture<V extends @Nullable Object> extends FluentFuture.TrustedFuture<V> {
  static <V extends @Nullable Object> ListenableFuture<V> create(

        urlIterator.remove()
      }
    }
```

### Troubleshooting

1. Valid cacheable responses are not being cached

Make sure you are reading responses fully as unless they are read fully, cancelled or stalled Responses will not be cached.

### Overriding normal cache behaviour