def test_difference(self):
s1 = HashSet(['J', 'I', 'E', 'R'])
s2 = HashSet(['H', 'N', 'E', 'R'])
s3 = s1.difference(s2)
assert s3.contains('N') == True
assert s3.contains('H') == True
assert s3.size() == 2
def test_difference(self):
hs1 = HashSet([1, 2, 3, 4])
hs2 = HashSet([3, 4, 5])
difference = hs1.difference(hs2)
assert difference.items() == [1, 2]
