Added pd.NA to nulls_fixture
@jorisvandenbossche 

I think we should do this. Simply xfailed issues up for discussion on how to resolve

Cool! Yes, I agree it's a good idea to add it, and skip for now where it is not yet supported should this use the dynamic-xfail pattern we've used elsewhere?

+1 on the idea Opened issues where I think applicable and updated comments accordingly Any other feedback here? this is ok

Assume u have opened an issue for the xfail u r adding Noted in tests - they are #31884 #31883 and #31881 Thanks all for feedback