swn can only be assigned once?

[wkitlasten]

I just pulled from main to make sure I was updated and started getting the following error after trying to load the pickle. Thoughts?

ngwf = swn.SwnMf6.from_pickle(ppth,gwf)

File "d:\modelling\surface-water-network\swn\modflow\_base.py", line 126, in from_pickle
    obj.swn = swn

  File "d:\modelling\surface-water-network\swn\modflow\_base.py", line 152, in swn
    raise AttributeError("swn property can only be set once")

AttributeError: swn property can only be set once

[mwtoews]

Aha, I just got caught by this one too. It's a misleading message, which needs to be fixed to close this issue. The reason why is that I've changed the arguments. Try this:

ngwf = swn.SwnMf6.from_pickle(ppth, model=gwf)

or if you have a SurfaceWaterNetwork object n:

ngwf = swn.SwnMf6.from_pickle(ppth, n, gwf)