public void updateWorkflowDef(WorkflowDef workflowDef) {
        workflowDef.setUpdateTime(System.currentTimeMillis());
        metadataDAO.updateWorkflowDef(workflowDef);
    }
@param workflowDef Workflow definition to be updated
core/src/main/java/com/netflix/conductor/service/MetadataServiceImpl.java