private void validateInstanceDirUnique(ActionReport report, AdminCommandContext context) {
CommandInvocation listInstances = cr.getCommandInvocation("list-instances", report, context.getSubject());
ParameterMap map = new ParameterMap();
map.add("whichTarget", theNode.getName());
listInstances.parameters(map);
listInstances.execute();
Properties pro = listInstances.report().getExtraProperties();
if (pro != null){
List<HashMap> instanceList = (List<HashMap>) pro.get("instanceList");
if (instanceList == null)
return;