docs: function _findMatchingMac(nodeLldpData, lldpMacList) {
          var relationsList = {};
          return Promise.all(
          _.forEach(_.keys(nodeLldpData.data), function (ethPort) {
              //validate mac first
              var lldpMac = catalogSearch.getPath(nodeLldpData.data[ethPort], 'chassis.mac');
              if (!lldpMac) {
                  throw new Error('cant find mac address in lldp data for node ' +
                      nodeLldpData.node + ' port ' + ethPort);
              }
              if (_validateMacStrFormat(lldpMac)) {
                  lldpMac = _adjustMacStrFormat(lldpMac);
                  if (lldpMacList.indexOf(lldpMac) >= 0) {
                      var singleEntry = {
                          destMac: nodeLldpData.data[ethPort].chassis.mac,
                          destPort: nodeLldpData.data[ethPort].port.ifname
                      };
                      relationsList[ethPort] = singleEntry;
                  }
              } else {
                  throw new Error('mac: ' + lldpMac + ' bad format',
                      +nodeLldpData.node + ' port ' + ethPort);
              }
          }))
          .then(function () {
              return Promise.resolve(relationsList);
          });
      }