code: def get_domain(self):
          
          points = ([poly.points for poly in self]+
                    [holes.points for holes in self.holes])
          points = np.concatenate(points, axis=0)
          return np.array([points.min(axis=0), points.max(axis=0)])
docs: :returns: opposite vertices of the bounding prism for this 
              object in the form of ndarray([min], [max])
          
          .. note:: This method automatically stores the solution in order
              to do not repeat calculations if the user needs to call it 
              more than once.