How to use the @optimizely/js-sdk-logging.setLogHandler function in @optimizely/js-sdk-logging

createInstance: function(config) {
    try {
      var hasLogger = false;
      config = config || {};

      // TODO warn about setting per instance errorHandler / logger / logLevel
      if (config.errorHandler) {
        logging.setErrorHandler(config.errorHandler);
      }
      if (config.logger) {
        // only set a logger in node if one is provided, by not setting we are noop-ing
        hasLogger = true;
        logging.setLogHandler(config.logger);
        // respect the logger's shouldLog functionality
        logging.setLogLevel(logging.LogLevel.NOTSET);
      }
      if (config.logLevel !== undefined) {
        logging.setLogLevel(config.logLevel);
      }

      try {
        configValidator.validate(config);
        config.isValidInstance = true;
      } catch (ex) {
        if (hasLogger) {
          logger.error(ex);
        } else {
          console.error(ex.message);
        }

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
var logging = require('@optimizely/js-sdk-logging');
var fns = require('./utils/fns');
var configValidator = require('./utils/config_validator');
var defaultErrorHandler = require('./plugins/error_handler');
var defaultEventDispatcher = require('./plugins/event_dispatcher/index.browser');
var enums = require('./utils/enums');
var loggerPlugin = require('./plugins/logger/index.react_native');
var Optimizely = require('./optimizely');
var eventProcessorConfigValidator = require('./utils/event_processor_config_validator');

var logger = logging.getLogger();
logging.setLogHandler(loggerPlugin.createLogger());
logging.setLogLevel(logging.LogLevel.INFO);

var DEFAULT_EVENT_BATCH_SIZE = 10;
var DEFAULT_EVENT_FLUSH_INTERVAL = 1000; // Unit is ms, default is 1s

/**
 * Entry point into the Optimizely Javascript SDK for React Native
 */
module.exports = {
  logging: loggerPlugin,
  errorHandler: defaultErrorHandler,
  eventDispatcher: defaultEventDispatcher,
  enums: enums,

  setLogger: logging.setLogHandler,
  setLogLevel: logging.setLogLevel,

* limitations under the License.
 */
require('promise-polyfill/dist/polyfill');
var logging = require('@optimizely/js-sdk-logging');
var fns = require('./utils/fns');
var configValidator = require('./utils/config_validator');
var defaultErrorHandler = require('./plugins/error_handler');
var defaultEventDispatcher = require('./plugins/event_dispatcher/index.browser');
var enums = require('./utils/enums');
var eventProcessor = require('@optimizely/js-sdk-event-processor');
var loggerPlugin = require('./plugins/logger');
var Optimizely = require('./optimizely');
var eventProcessorConfigValidator = require('./utils/event_processor_config_validator');

var logger = logging.getLogger();
logging.setLogHandler(loggerPlugin.createLogger());
logging.setLogLevel(logging.LogLevel.INFO);

var MODULE_NAME = 'INDEX_BROWSER';

var DEFAULT_EVENT_BATCH_SIZE = 10;
var DEFAULT_EVENT_FLUSH_INTERVAL = 1000; // Unit is ms, default is 1s

var hasRetriedEvents = false;
/**
 * Entry point into the Optimizely Browser SDK
 */
module.exports = {
  logging: loggerPlugin,
  errorHandler: defaultErrorHandler,
  eventDispatcher: defaultEventDispatcher,
  enums: enums,

createInstance: function(config) {
    try {
      config = config || {};

      // TODO warn about setting per instance errorHandler / logger / logLevel
      if (config.errorHandler) {
        logging.setErrorHandler(config.errorHandler);
      }
      if (config.logger) {
        logging.setLogHandler(config.logger);
        // respect the logger's shouldLog functionality
        logging.setLogLevel(logging.LogLevel.NOTSET);
      }
      if (config.logLevel !== undefined) {
        logging.setLogLevel(config.logLevel);
      }

      try {
        configValidator.validate(config);
        config.isValidInstance = true;
      } catch (ex) {
        logger.error(ex);
        config.isValidInstance = false;
      }

      // Explicitly check for null or undefined

createInstance: function(config) {
    try {
      config = config || {};

      // TODO warn about setting per instance errorHandler / logger / logLevel
      if (config.errorHandler) {
        logging.setErrorHandler(config.errorHandler);
      }
      if (config.logger) {
        logging.setLogHandler(config.logger);
        // respect the logger's shouldLog functionality
        logging.setLogLevel(logging.LogLevel.NOTSET);
      }
      if (config.logLevel !== undefined) {
        logging.setLogLevel(config.logLevel);
      }

      try {
        configValidator.validate(config);
        config.isValidInstance = true;
      } catch (ex) {
        logger.error(ex);
        config.isValidInstance = false;
      }

      // Explicitly check for null or undefined

sinon.stub(datafileManager, 'HttpPollingDatafileManager').returns({
      start: sinon.stub(),
      stop: sinon.stub(),
      get: sinon.stub().returns(null),
      on: sinon.stub().returns(function() {}),
      onReady: sinon.stub().returns({ then: function() {} }),
    });
    globalStubErrorHandler = {
      handleError: sinon.stub(),
    };
    logging.setErrorHandler(globalStubErrorHandler);
    logging.setLogLevel('notset');
    stubLogHandler = {
      log: sinon.stub(),
    };
    logging.setLogHandler(stubLogHandler);
  });