final DataTreeIdentifier<Subnet> dataTreeIid = new DataTreeIdentifier<>(LogicalDatastoreType.CONFIGURATION,
MefInterfaceUtils.getSubnetsInstanceIdentifier());
subnetListenerRegistration = dataBroker.registerDataTreeChangeListener(dataTreeIid, this);
final DataTreeIdentifier<Subnet> dataTreeIid = new DataTreeIdentifier<>(LogicalDatastoreType.CONFIGURATION,
MefInterfaceUtils.getSubnetsInstanceIdentifier());
subnetListenerRegistration = dataBroker.registerDataTreeChangeListener(dataTreeIid, this);