/**
   * Precondition tester for {@code Iterator.remove()} that throws an exception with a consistent
   * error message.
   */
  static void checkRemove(boolean canRemove) {
    checkState(canRemove, "no calls to next() since the last call to remove()");
  }

  private CollectPreconditions() {}

1. Click **Management**.
1. Click **Index Patterns**.
1. Click **Create index pattern** button
1. Input "fess\_log\*" to the textbox of **index pattern**.
1. Click **Next step**.
1. Set "requestedAt" to the **Time Filter field name**.
1. Click **Create index pattern**.
1. Click **Saved Objects**.
1. Click **Import** and select "fess\_log.ndjson" to import example settings.

The only new thing is the `callbacks=invoices_callback_router.routes` as an argument to the *path operation decorator*. We'll see what that is next.

## Documenting the callback { #documenting-the-callback }

The actual callback code will depend heavily on your own API app.

And it will probably vary a lot from one app to the next.

It could be just one or two lines of code, like:

```Python
callback_url = "https://example.com/api/v1/invoices/events/"

  }

  private static final class MyIntegerDomain extends DiscreteDomain<Integer> {
    static final DiscreteDomain<Integer> DELEGATE = DiscreteDomain.integers();

    @Override
    public Integer next(Integer value) {
      return DELEGATE.next(value);
    }

    @Override
    public Integer previous(Integer value) {
      return DELEGATE.previous(value);
    }

        continue
      }

      // Search for the certificate in the chain that signed this certificate. This is typically
      // the next element in the chain, but it could be any element.
      val i = queue.iterator()
      while (i.hasNext()) {
        val signingCert = i.next() as X509Certificate
        if (verifySignature(toVerify, signingCert, result.size - 1)) {
          i.remove()
          result.add(signingCert)

      @Override
      public boolean hasNext() {
        return entryItr.hasNext();
      }

      @Override
      public V next() {
        return entryItr.next().getValue();
      }
    };
  }

  @Override
  public boolean contains(@Nullable Object object) {
    return object != null && Iterators.contains(iterator(), object);
  }

  @Override

 */
public class SmbComLogoffAndX extends AndXServerMessageBlock {

    /**
     * Creates a new SMB1 logoff request to end a user session.
     *
     * @param config the CIFS configuration
     * @param andx the next command in the AndX chain, or null
     */
    public SmbComLogoffAndX(final Configuration config, final ServerMessageBlock andx) {
        super(config, SMB_COM_LOGOFF_ANDX, andx);
    }

    @Override

    if (!elements.hasNext()) {
      return of();
    }
    E first = elements.next();
    if (!elements.hasNext()) {
      return of(first);
    }

    Set<E> delegate = Sets.newLinkedHashSet();
    delegate.add(checkNotNull(first));
    do {
      delegate.add(checkNotNull(elements.next()));
    } while (elements.hasNext());

    return unsafeDelegate(delegate);
  }

    checkNotNull(predicate);
    Iterator<T> iterator = removeFrom.iterator();
    while (iterator.hasNext()) {
      T next = iterator.next();
      if (predicate.apply(next)) {
        iterator.remove();
        return next;
      }
    }
    return null;
  }

  /**
   * Determines whether two iterables contain equal elements in the same order. More specifically,

 */
fun interface Dns {
  /**
   * Returns the IP addresses of `hostname`, in the order they will be attempted by OkHttp. If a
   * connection to an address fails, OkHttp will retry the connection with the next address until
   * either a connection is made, the set of IP addresses is exhausted, or a limit is exceeded.
   */
  @Throws(UnknownHostException::class)
  fun lookup(hostname: String): List<InetAddress>