private void send(Send send) throws IOException {
        try {
            netOutBuffer = send;
            flushNetOutBufferAndUpdateInterestOps();
        } catch (IOException e) {
            setSaslState(SaslState.FAILED);
            throw e;
        }
    }
Sends a SASL client token to server if required. This may be an initial token to start
SASL token exchange or response to a challenge from the server.
@return true if a token was sent to the server
clients/src/main/java/org/apache/kafka/common/security/authenticator/SaslClientAuthenticator.java