@Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
protected HostService hostService;
// code omitted ...
@Deactivate
public void deactivate() {
hostService.removeListener(hostListener);
// TODO can be replaced with this.clearAcl()
flowRuleService.removeFlowRulesById(appId);
aclStore.clearAcl();
log.info("Stopped");
}