How to use the iotagent-node-lib.setConfigurationHandler function in iotagent-node-lib

iotAgentLib.activate(config.getConfig().iota, function (error) {
        if (error) {
            return callback(error);
        } else {
            winston.info('iotagent-node-lib activated');
            iotAgentLib.setProvisioningHandler(registerDevice);
            iotAgentLib.setConfigurationHandler(registerConfiguration);

            // Enables all the plugins
            iotAgentLib.addUpdateMiddleware(iotAgentLib.dataPlugins.attributeAlias.update);
            iotAgentLib.addUpdateMiddleware(iotAgentLib.dataPlugins.addEvents.update);
            iotAgentLib.addUpdateMiddleware(iotAgentLib.dataPlugins.expressionTransformation.update);
            iotAgentLib.addUpdateMiddleware(iotAgentLib.dataPlugins.multiEntity.update);
            iotAgentLib.addUpdateMiddleware(iotAgentLib.dataPlugins.timestampProcess.update);

            iotAgentLib.addDeviceProvisionMiddleware(iotAgentLib.dataPlugins.bidirectionalData.deviceProvision);
            iotAgentLib.addConfigurationProvisionMiddleware(iotAgentLib.dataPlugins.bidirectionalData.groupProvision);
            iotAgentLib.addNotificationMiddleware(iotAgentLib.dataPlugins.bidirectionalData.notification);

            async.waterfall([
                loadTypesFromConfig,
                loadServices,
                loadDevices