def convert_to_multi_line(self):
"""Since we may have doors, I want to convert polygon with doors into MultiLineString"""
lines = []
door_line = MultiLineString(
[LineString(pnt_pair) for pnt_pair in self.doors])
exterior_line = MultiLineString(
[poly.exterior for poly in self.cvx_polys])
self.multi_line = exterior_line.symmetric_difference(door_line)
return self.multi_line
