public NetworkReceive networkReceive() {
        return networkReceive;
    }
Return the applicable {@link NetworkReceive} instance, if any. For the client
side this may be a response that has been partially read, a non-null instance
that has had no data read into it yet, or null; if it is non-null then this
is the instance that data should initially be read into during
re-authentication. For the server side this is mandatory and it must contain
the {@code SaslHandshakeRequest} that has been received on the server and
that initiates re-authentication.

@return the applicable {@link NetworkReceive} instance, if any
clients/src/main/java/org/apache/kafka/common/network/ReauthenticationContext.java