code: @RequestMapping(method = RequestMethod.GET, value = "/workflowInstance/{woinRefNum}",
              produces = {MediaType.APPLICATION_JSON_VALUE, MediaType.TEXT_XML_VALUE})
      public ResponseEntity<WorkflowInstanceRestModel> find( @PathVariable long woinRefNum ){
          WorkflowInstanceState woin = facade.findWorkflowInstance( woinRefNum, null );
          if( woin == null ){
              return new ResponseEntity<>( HttpStatus.NOT_FOUND );
          }
          else{
              return new ResponseEntity<>( createInstanceModel( woin ), HttpStatus.OK );
          }
      }
docs: Finds a workflow instance.
  
  <pre>
  Request:  GET /workflowInstance/1
  Response: OK {refNum: 1, workflowName: "credit.step1", workflowVersion: null, label1: "one", label2: null, status: NEW}
  Response: NOT_FOUND, if no such workflow instance exists
  </pre>