code: private void validateClusterNameOfWorkflowInstance( long woinRefNum ){
          WorkflowInstance woin = workflowInstanceService.find( woinRefNum );
          String clusterName = config.getClusterName();
          if( !ObjectUtils.equals( clusterName, woin.getClusterName() ) ){
              throw new IllegalArgumentException( "The workflow instance " + woinRefNum + " is not executed by this cluster " + clusterName );
          }
      }
docs: Please see the class level documentation for a reasoning on this method.