def serialized(self):
        to_ret = {}
        for group, requirements in self.items():
            to_ret[group] = [str(requirement) for requirement in requirements]
        return to_ret
def test_brewster_angle():
    m1 = Medium('m1', n=1)
    m2 = Medium('m2', n=1.33)
    assert ae(brewster_angle(m1, m2), 0.93, 2)
    m1 = Medium('m1', permittivity=e0, n=1)
    m2 = Medium('m2', permittivity=e0, n=1.33)
    assert ae(brewster_angle(m1, m2), 0.93, 2)
    assert ae(brewster_angle(1, 1.33), 0.93, 2)