code: func New(cfg Collector, nodeInfo collectors.NodeInfo, rels *ContainerTaskRels) (Collector, chan producers.MetricsMessage) {
  	c := cfg
  	c.log = logrus.WithFields(logrus.Fields{"collector": "mesos-agent"})
  	c.nodeInfo = nodeInfo
  	c.metricsChan = make(chan producers.MetricsMessage)
  	c.ContainerTaskRels = rels
  	return c, c.metricsChan
  }
docs: // New creates a new instance of the Mesos agent collector (poller).