GammaLib

Table column classes have a nulval() method that allows setting of the NULL value. Changing the NULL value has in principle an impact on the data in a column. Thus, if the data are already loaded one would need to screen the data in order to update the NULL value. This is not done so far. Any loaded data are unaffected by a change of the NULL value.

Maybe this is the desired property, yet in this case one should at least throw an error to signal to the user that the NULL value cannot be changed for loaded data. I guess this should be the correct boundary condition for this case.