modify doc string of `surplus_harvesters`
to indicate that it also accepts gas geysers
@@ -1170,7 +1170,9 @@ class Unit:
@property
def surplus_harvesters(self) -> int:
""" Returns a positive int if unit has too many harvesters mining,
- a negative int if it has too few mining."""
+ a negative int if it has too few mining.
+ will only works for townhalls, and gasgeysers
+ """
return self._proto.assigned_harvesters - self._proto.ideal_harvesters
@property_immutable_cache
