missing checkValidity in MergedBus#getFictitiousP0

[jonenst]

Describe the current behavior

in nodebreakertopology, when you toggle a switch which invalidates a view, getting the fictitiousP0 and fictitiousQ0 throws an exception:

        Bus bus = vl.getBusView().getMergedBus(id);
        nodebreakerbusviewbus.setFictitiousP0(2.0);
        
        System.out.println(nodebreakerbusviewbus.getFictitiousP0());
        sw.setOpen(true);
        System.out.println(nodebreakerbusviewbus.getFictitiousP0());

2.0
Exception in thread "main" com.powsybl.commons.PowsyblException: Bus has been invalidated
	at com.powsybl.iidm.network.impl.CalculatedBusImpl.checkValidity(CalculatedBusImpl.java:59)
	at com.powsybl.iidm.network.impl.CalculatedBusImpl.getFictitiousP0(CalculatedBusImpl.java:148)

in busbreaker for the exact same code it returns , it returns 0:

2.0
0.0

Describe the expected behavior

it should throw. the buses set is empty and valid is false. It should behave like the nodebreakertopology. All other methods call checkValidity()

Describe the steps

No response

Environment

No response

Relevant Log Output

No response

Extra Information

https://github.com/powsybl/powsybl-core/blob/main/iidm/iidm-impl/src/main/java/com/powsybl/iidm/network/impl/MergedBus.java#L134
https://github.com/powsybl/powsybl-core/blob/main/iidm/iidm-impl/src/main/java/com/powsybl/iidm/network/impl/MergedBus.java#L154