code: function createLoggerStream(name, level, logglyConfig) {
      const streams = [process.stdout];
      if (logglyConfig.enabled) {
          const logglyStream = new LogglyStream({
              token: logglyConfig.token,
              subdomain: logglyConfig.subdomain,
              name,
              environment: logglyConfig.environment,
          });
          streams.push(logglyStream);
      }
      return new UnionStream({ streams });
  }
docs: singleton to create a logging instance based on config