public void reset() {
        this.state = State.UNCHALLENGED;
        this.authOptions = null;
        this.authScheme = null;
        this.pathPrefix = null;
    }
This class represents the actual state of authentication handshake including the current {@link AuthScheme}
used for request authorization as well as a collection of backup authentication options if available.

@since 4.5
httpclient5/src/main/java/org/apache/hc/client5/http/auth/AuthExchange.java