docs: def _cx_counters_psutil(self, tags=None):
          """
          Collect metrics about interfaces counters using psutil
          """
          tags = [] if tags is None else tags
          for iface, counters in iteritems(psutil.net_io_counters(pernic=True)):
              metrics = {
                  'bytes_rcvd': counters.bytes_recv,
                  'bytes_sent': counters.bytes_sent,
                  'packets_in.count': counters.packets_recv,
                  'packets_in.error': counters.errin,
                  'packets_out.count': counters.packets_sent,
                  'packets_out.error': counters.errout,
              }
              self._submit_devicemetrics(iface, metrics, tags)