code: private void ensureQuorumPresent(Operation op) {
          QuorumServiceImpl quorumService = operationService.nodeEngine.getQuorumService();
          quorumService.ensureQuorumPresent(op);
      }
docs: Ensures that the quorum is present if the quorum is configured and the operation service is quorum aware.
  
  @param op the operation for which the quorum must be checked for presence
  @throws QuorumException if the operation requires a quorum and the quorum is not present