private static function setCapabilities($capabilities) {

        $supported_capabilities = array(
            'xmlrpc' => array('http://www.xmlrpc.com/spec', 1),
            'system.multicall' => array('http://www.xmlrpc.com/discuss/msgReader$1208', 1),
            'introspection' => array('http://phpxmlrpc.sourceforge.net/doc-2/ch10.html', 2),
            'nil' => array('http://www.ontosys.com/xml-rpc/extensions.php', 1),
            'faults_interop' => array('http://xmlrpc-epi.sourceforge.net/specs/rfc.fault_codes.php', 20010516),
            'json-rpc' => array('http://www.jsonrpc.org/specification', 2)
        );

        foreach ( $supported_capabilities as $capability => $values ) {

            $capabilities->add($capability, $values[0], $values[1]);

        }

    }