code: public OperationFuture<List<Server>> revertToSnapshot(Server... servers) {
          List<Server> serverList = Arrays.asList(servers);
  
          List<JobFuture> futures = serverList.stream()
              .map(this::findByRef)
              .flatMap(metadata -> metadata.getDetails().getSnapshots().stream())
              .map(snapshot ->
                  baseServerResponse(
                      client.revertToSnapshot(snapshot.getServerId(), snapshot.getId())
                  )
                  .jobFuture()
              )
              .collect(toList());
  
          return new OperationFuture<>(
              serverList,
              new ParallelJobsFuture(futures)
          );
      }
docs: Revert a set of servers to snapshot
  @param servers server references
  @return OperationFuture wrapper for list of ServerRef