code: @RequestMapping(method = RequestMethod.GET, value = "/workflowInstance/search",
              produces = {MediaType.APPLICATION_JSON_VALUE, MediaType.TEXT_XML_VALUE})
      public ResponseEntity<List<WorkflowInstanceRestModel>> findInstances( @RequestParam(required = false) String label1,
                                                                            @RequestParam(required = false) String label2,
                                                                            @RequestParam(required = false) Boolean activeOnly ){
          if( activeOnly == null ){
              activeOnly = true;
          }
          label1 = StringUtils.trimToNull( label1 );
          label2 = StringUtils.trimToNull( label2 );
          List<WorkflowInstanceState> woins = facade.findWorkflowInstancesByLabels( label1, label2, activeOnly );
          return new ResponseEntity<>( createInstancesModel( woins ), HttpStatus.OK );
      }
docs: Searches workflow instance's that match the given criteria.
  
  <pre>
  Request:  GET /workflowInstance/search?label1=aClientId
  Response: OK, [{refNum: 1, workflowName: "credit.step1", workflowVersion: null, label1: "aClientId", label2: null, status: NEW}, {refNum: 2, workflowName: "credit.client.step1", workflowVersion: null, label1: "aClientId", label2: "anotherIdentificator", status: NEW}]
  </pre>