*/
@RequestMapping("workspace-graphHistoryProcessInstance")
public void graphHistoryProcessInstance(
@RequestParam("processInstanceId") String processInstanceId,
HttpServletResponse response) throws Exception {
Command<InputStream> cmd = new HistoryProcessInstanceDiagramCmd(
processInstanceId);
InputStream is = processEngine.getManagementService().executeCommand(
cmd);
response.setContentType("image/png");