def test_Cache():
c = utils.Cache()
c[5] = "Spam"
assert 5 in c
assert c[5] == "Spam"
assert 6 not in c
def test_Cache_evict():
c = utils.Cache(2)
c[5] = "a"
c[6] = "b"
c[7] = "c"
assert set(c.keys()) == {6, 7}
assert c[6] == "b"
assert c[7] == "c"
c[8] = "d"
assert set(c.keys()) == {7, 8}
assert c[7] == "c"
c[9] = "e"
assert set(c.keys()) == {7, 9}