:returns: opposite vertices of the bounding prism for this 
            object.
        :rtype: ndarray([min], [max])

def get_domain(self):
        """
        :returns: opposite vertices of the bounding prism for this 
            object.
        :rtype: ndarray([min], [max])
        """
        points = np.vstack([place.get_domain() for place in self])
        return np.array([points.min(axis=0), points.max(axis=0)])