* #add(Object, int)} alone <b>will not</b> change the behavior of {@link #add(Object)}, which can
 * lead to unexpected behavior. In this case, you should override {@code add(Object)} as well,
 * either providing your own implementation, or delegating to the provided {@code standardAdd}
 * method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code

 *   <li>It is easy for the user to ensure that listeners are never invoked while holding locks.
 * </ul>
 *
 * The last point is subtle. Often the observable object will be managing its own internal state
 * using a lock, however it is dangerous to dispatch listeners while holding a lock because they
 * might run on the {@code directExecutor()} or be otherwise re-entrant (call back into your

 *
 * ### Server Authentication
 *
 * This is the most common form of TLS authentication: clients verify that servers are trusted and
 * that they own the hostnames that they represent. Server authentication is required.
 *
 * To perform server authentication:
 *
 *  * The server's handshake certificates must have a [held certificate][HeldCertificate] (a

   *
   * Use the `request` of the [networkResponse] field to get the wire-level request that was
   * transmitted. In the case of follow-ups and redirects, also look at the `request` of the
   * [priorResponse] objects, which have its own [priorResponse].
   */
  @get:JvmName("request") val request: Request,
  /** Returns the HTTP protocol, such as [Protocol.HTTP_1_1] or [Protocol.HTTP_1_0]. */
  @get:JvmName("protocol") val protocol: Protocol,

    }

    /**
     * Returns true if the request contains conditions that save the server from sending a response
     * that the client has locally. When a request is enqueued with its own conditions, the built-in
     * response cache won't be used.
     */
    private fun hasConditions(request: Request): Boolean =
      request.header("If-Modified-Since") != null || request.header("If-None-Match") != null

## 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/"

#### Per-Connection Locks

 *
 * The format of the logs created by this class should not be considered stable and may
 * change slightly between releases. If you need a stable logging format, use your own interceptor.
 */
class HttpLoggingInterceptor
  @JvmOverloads
  constructor(
    private val logger: Logger = Logger.DEFAULT,
  ) : Interceptor {
    @Volatile private var headersToRedact = emptySet<String>()

 * an existing external tool is required.
 *
 * See https://stackoverflow.com/questions/61929216/how-to-log-tlsv1-3-keys-in-jsse-for-wireshark-to-decode-traffic
 *
 * Steps to run in your own code
 *
 * 1. In your main method `WireSharkListenerFactory.register()`
 * 2. Create Listener factory `val eventListenerFactory = WireSharkListenerFactory(

 * the behavior of {@link #addAll}, which can lead to unexpected behavior. In this case, you should
 * override {@code addAll} as well, either providing your own implementation, or delegating to the
 * provided {@code standardAddAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code