code: def killall(self, everywhere=False):
      
      with self._NAILGUN_KILL_LOCK:
        for proc in self._iter_nailgun_instances(everywhere):
          logger.info('killing nailgun server pid={pid}'.format(pid=proc.pid))
          proc.terminate()
docs: Kills all nailgun servers started by pants.
  
         :param bool everywhere: If ``True``, kills all pants-started nailguns on this machine;
                                 otherwise restricts the nailguns killed to those started for the
                                 current build root.