@ -260,7 +260,7 @@ class Shape(PositionableImpl, LayerableImpl, DoseableImpl, Rotatable, Mirrorable
for polygon in self.to_polygons():
# Get rid of unused gridlines (anything not within 2 lines of the polygon bounds)
bounds = polygon.get_bounds()
if not bounds:
if bounds is None:
continue
mins, maxs = bounds