code: function requestId(options){
  
      options = extend({}, DEFAULTS);
  
      return function requestIdMiddleware(req, res, next){
  
          let id = _getId(req, options);
          let attributeName = options.attributeName;
  
          // console.log('requestid', id);
  
          /*
           * Want to expose the genrated
           * id in the request and response
           */
          req[attributeName] = id;
  
          if(res.req) res.req[attributeName] = id;
  
          /*
           * We send a header with the required
           * id...
           */
          if(options.resHeader) {
              res.set(options.resHeader, id);
          }
  
          next();
      }
  }
docs: /*
  We should be using [correlation-id][1] to
  ensure we have the same ID per unique req.
  
  [1]:https://github.com/toboid/correlation-id