@Override
    public HttpResourceFetcher exceptionHandler(Handler<Throwable> exceptionHandler) {
        this.exceptionHandler = exceptionHandler;
        return this;
    }
Fetch HTTP and HTTPS resources, with Auth options including BASIC and various OAuth2
permutations.

<ul>
  <li>auth: auth type, one of {@link AuthType}. Otherwise <tt>None</tt> by default.<li>
</ul>

Refer to {@link AuthType} for available options, such as BASIC, OAuth2, Keycloak, etc.

@see AuthType
@author Marc Savy {@literal <marc@rhymewithgravy.com>}
gateway/engine/vertx-polling/src/main/java/io/apiman/gateway/engine/vertx/polling/fetchers/HttpResourceFetcher.java