def test_contains(self):
s = HashSet()
s.add('S')
assert s.contains('S') == True
assert s.contains('H') == False
s.add('H')
assert s.contains('H') == True
assert s.contains('S') == True
def test_remove(self):
hs = HashSet([1, 2, 3])
assert hs.items() == [1, 2, 3]
assert hs.contains(3) == True
assert hs.size == 3
# remove item
hs.remove(3)
assert hs.items() == [1, 2]
assert hs.contains(3) == False
assert hs.size == 2
with self.assertRaises(KeyError):
hs.remove(3)
def test_contains(self):
hs = HashSet([1, 2, 3])
assert hs.contains(2) == True
assert hs.contains(4) == False