SOP on the 737 fleet in BA. As 'AVCP' says - think about the advisability of it, choose the engine carefully with a view to the turn on stand and check hydraulics/elec/weight considerations too. I seem to recall also that the 200 series lost the cabin lights if you shut ?number 2?
Wait then for the stand change with AGNIS u/s, no ground staff and an opposite turn-on.................
. Good for a laugh.