code: public void addLeases(List<? extends VirtualMachineLease> leases) {
          if (leases != null && !leases.isEmpty()) {
              for(VirtualMachineLease l: leases)
                  leaseBlockingQueue.offer(l);
          }
      }
docs: Add new leases to be used for next scheduling iteration. Leases with IDs previously added cannot be added
  again. If duplicates are found, the scheduling iteration throws an exception and is available via the
  scheduling result callback. See {@link TaskScheduler#scheduleOnce(List, List)} for details on behavior upon
  encountering an exception. This method can be called anytime without impacting any currently running scheduling
  iterations. The leases will be used in the next scheduling iteration.
  @param leases New leases to use for scheduling.