code: @PreAuthorize("hasRole('ROLE_TWE_ADMIN')")
      @RequestMapping(method = RequestMethod.POST, value = "/workflow/instances/{woinRefNum}")
      public String performActionOnInstance( RedirectAttributes model, @PathVariable long woinRefNum, @RequestParam() String action ){
          if( "abort".equals( action ) || "suspend".equals( action ) || "resume".equals( action ) || "retry".equals( action ) ){
              try{
                  if( "abort".equals( action ) ){
                      facade.abortWorkflowInstance( woinRefNum );
                      model.addFlashAttribute( "successMessage", "workflow.instance.action.abort.success" );
                  }
                  else if( "suspend".equals( action ) ){
                      facade.suspendWorkflowInstance( woinRefNum );
                      model.addFlashAttribute( "successMessage", "workflow.instance.action.suspend.success" );
                  }
                  else if( "resume".equals( action ) ){
                      facade.resumeWorkflowInstance( woinRefNum );
                      model.addFlashAttribute( "successMessage", "workflow.instance.action.resume.success" );
                  }
                  else if( "retry".equals( action ) ){
                      facade.retryWorkflowInstance( woinRefNum );
                      model.addFlashAttribute( "successMessage", "workflow.instance.action.retry.success" );
                  }
              }
              catch( UnexpectedStatusException e ){
                  model.addFlashAttribute( "errorMessage", "workflow.instance.action.error.unexpectedstatus" );
              }
          }
          else{
              model.addFlashAttribute( "unknownAction", action );
              model.addFlashAttribute( "errorMessage", "workflow.instance.action.error.unknownaction" );
          }
          return "redirect:" + configuration.getConsoleMappingPrefix() + "/console/workflow/instances/" + woinRefNum;
      }
docs: Aborts, suspends or resumes a workflow instance or retries the last failed operation
  on the instance.<br>
  Returns a redirect for a GET-after-POST.