class KascadeLdfTest(unittest.TestCase):
    def setUp(self):
        self.ldf = KascadeLdf()

    def test_cache_c_s_value(self):
        # change s value
        self.ldf._s += .1

        self.ldf._cache_c_s_value()
        expected = self.ldf._c(self.ldf._s)

        self.assertEqual(expected, self.ldf._c_s)

    def test_init_stores_Ne_and_s(self):
        Ne = sentinel.Ne
        s = sentinel.s

        with patch.object(KascadeLdf, '_cache_c_s_value') as mock_cache:
            ldf = KascadeLdf(Ne, s)

        self.assertIs(ldf._Ne, Ne)
        self.assertIs(ldf._s, s)

    def test_init_calls_cache_c_s_value(self):
        with patch.object(KascadeLdf, '_cache_c_s_value') as mock_cache:
            sim = KascadeLdf()
            mock_cache.assert_called_once_with()
class KascadeLdfTest(unittest.TestCase):
    def setUp(self):
        self.ldf = KascadeLdf()

    def test_cache_c_s_value(self):
        # change s value
        self.ldf._s += 0.1

        self.ldf._cache_c_s_value()
        expected = self.ldf._c(self.ldf._s)

        self.assertEqual(expected, self.ldf._c_s)

    def test_init_stores_Ne_and_s(self):
        Ne = sentinel.Ne
        s = sentinel.s

        with patch.object(KascadeLdf, "_cache_c_s_value") as mock_cache:
            ldf = KascadeLdf(Ne, s)

        self.assertIs(ldf._Ne, Ne)
        self.assertIs(ldf._s, s)

    def test_init_calls_cache_c_s_value(self):
        with patch.object(KascadeLdf, "_cache_c_s_value") as mock_cache:
            sim = KascadeLdf()
            mock_cache.assert_called_once_with()