docs: def getLockByID(self, lockid):
          """Convert a Lock identifier into an actual Lock instance.
          @param lockid: a locks.MasterLock or locks.WorkerLock instance
          @return: a locks.RealMasterLock or locks.RealWorkerLock instance
          """
          assert isinstance(lockid, (locks.MasterLock, locks.WorkerLock))
          if lockid not in self.locks:
              self.locks[lockid] = lockid.lockClass(lockid)
          # if the master.cfg file has changed maxCount= on the lock, the next
          # time a build is started, they'll get a new RealLock instance. Note
          # that this requires that MasterLock and WorkerLock (marker) instances
          # be hashable and that they should compare properly.
          return self.locks[lockid]