code: function(qName, type, offset, limit) {
      var q = queue.get(qName);
      if (!(offset >= 0)) {
        offset = 0;
      }
      if (!(limit >= 0)) {
        limit = 30;
      }
      if (type === 'wait' || type === 'active') {
        return q.getJobs(type, 'LIST', offset, offset + limit - 1).then(function(jobs) {
          return Promise.all(_.map(jobs, function(job) {
            if (!job) {
              return null;
            }
            return job.getState().then(function(state) {
              job.state = state;
              return job;
            });
          }));
        });
      } else if (type === 'delayed') {
        return q.getJobs(type, 'ZSET', offset, offset + limit - 1).then(function(jobs) {
          return Promise.all(_.map(jobs, function(job) {
            if (!job) {
              return null;
            }
            return job.getState().then(function(state) {
              job.state = state;
              return job;
            });
          }));
        });
      } else if (type === 'completed' || type === 'failed') {
        var client = redis.client();
        var key = 'bull:' + qName + ':' + type;
        return client.smembersAsync(key).then(function(ids) {
          var _ids = ids.slice(offset, offset + limit);
          return Promise.all(_.map(_ids, function(id) {
            return q.getJob(id).then(function(job) {
              if (!job) {
                return null;
              }
              return job.getState().then(function(state) {
                job.state = state;
                return job;
              });
            });
          }));
        });
      }
      throw new Error('You must provide a valid job type.');
    }
docs: Fetch a number of jobs of certain type
  @param {String} qName Queue name
  @param {String} type Job type: {wait|active|delayed|completed|failed}
  @param {Number} offset Index offset (optional)
  @param {Number} limit Limit of the number of jobs returned (optional)
  @returns {Promise} A promise that resolves to an array of jobs