public Integer getProxyPort() {
        return proxyPort;
    }
Returns the port of the guacd instance to use. If the port of the default
guacd instance should be used instead, null is returned.

@return
    The port of the guacd instance to use, or null if the port of the
    default guacd instance should be used.
extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/connection/ConnectionModel.java