def METHOD_NAME(self):
    """Check calculation of joint P(A,B)"""
    conditional = DiscreteConditional(A, [B], "1/2 2/1")
    prior = DiscreteConditional(B, "1/2")
    # P(A,B) = P(A|B) * P(B) = P(B) * P(A|B)
    for actual in [prior * conditional, conditional * prior]:
        self.assertEqual(2, actual.nrFrontals())
        for v, value in actual.enumerate():
            self.assertAlmostEqual(actual(v), conditional(v) * prior(v))