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

ReactNativeLogger.prototype.log = function(level, message) {
  var formattedMessage = sprintf('[OPTIMIZELY] - %s %s %s', getLogLevelName(level), new Date().toISOString(), message);
  switch (level) {
    case LogLevel.INFO: console.info(formattedMessage); break;
    case LogLevel.ERROR:
    case LogLevel.WARNING: console.warn(formattedMessage); break;
    case LogLevel.DEBUG:
    case LogLevel.NOTSET: console.log(formattedMessage); break;
  }
};