public Optional<NetworkReceive> pollResponseReceivedDuringReauthentication() {
        return authenticator.pollResponseReceivedDuringReauthentication();
    }
Return the (always non-null but possibly empty) client-side
{@link NetworkReceive} response that arrived during re-authentication but
is unrelated to re-authentication. This corresponds to a request sent
prior to the beginning of re-authentication; the request was made when the
channel was successfully authenticated, and the response arrived during the
re-authentication process.

@return client-side {@link NetworkReceive} response that arrived during
        re-authentication that is unrelated to re-authentication. This may
        be empty.
clients/src/main/java/org/apache/kafka/common/network/KafkaChannel.java