code: function listen(self, address, port, addressType, backlog, exclusive) {
      /* TODO Index servers by a self-assigned identifier and the process
       * identifier so messages intended for previous instances do not pass
       * through. */
      servers[port] = self; // Index servers by port.
      self._port = port; // Remember the requested port for close.
      process.send({
          cmd: 'CLUSTER_LISTEN',
          port: port,
          address: address, // For confirmation purposes only.
          addressType: addressType, // We allow the supervisor to infer the address type.
          backlog: backlog, // Used to confirm uniformity of worker requests.
          exclusive: exclusive // TODO use this on the other end
      });
  }
docs: This performs the actual listen when the argument forms have been normalized above. /*jshint -W072