#vulnerable code 
                                @Override
    protected void setSslDomain(Transport transport) throws TransportException
    {
        // Codes_SRS_AMQPSDEVICEAUTHENTICATIONCBS_12_011: [The function shall set get the sasl layer from the transport.]
        Sasl sasl = transport.sasl();
        // Codes_SRS_AMQPSDEVICEAUTHENTICATIONCBS_12_012: [The function shall set the sasl mechanism to PLAIN.]
        sasl.setMechanisms("ANONYMOUS");

        // Codes_SRS_AMQPSDEVICEAUTHENTICATIONCBS_12_013: [The function shall set the SslContext on the domain.]
        SslDomain domain = null;
        try
        {
            domain = makeDomain(this.deviceClientConfig.getSasTokenAuthentication().getSSLContext());
        }
        catch (IOException e)
        {
            logger.LogDebug("setSslDomain has thrown exception: %s", e.getMessage());
            throw new TransportException(e);
        }
        // Codes_SRS_AMQPSDEVICEAUTHENTICATIONCBS_12_014: [The function shall set the domain on the transport.]
        transport.ssl(domain);
    } 
                            #location 13 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    protected void setSslDomain(Transport transport) throws TransportException
    {
        // Codes_SRS_AMQPSDEVICEAUTHENTICATIONCBS_12_011: [The function shall set get the sasl layer from the transport.]
        Sasl sasl = transport.sasl();
        // Codes_SRS_AMQPSDEVICEAUTHENTICATIONCBS_12_012: [The function shall set the sasl mechanism to PLAIN.]
        sasl.setMechanisms("ANONYMOUS");

        // Codes_SRS_AMQPSDEVICEAUTHENTICATIONCBS_12_013: [The function shall set the SslContext on the domain.]
        SslDomain domain = null;
        try
        {
            domain = makeDomain(this.deviceClientConfig.getAuthenticationProvider().getSSLContext());
        }
        catch (IOException e)
        {
            logger.LogDebug("setSslDomain has thrown exception: %s", e.getMessage());
            throw new TransportException(e);
        }
        // Codes_SRS_AMQPSDEVICEAUTHENTICATIONCBS_12_014: [The function shall set the domain on the transport.]
        transport.ssl(domain);
    }