'L{set} should behave like the expected set interface.'

def test_set(self):

    a = set()
    a.add('b')
    a.add('c')
    a.add('a')
    b = list(a)
    b.sort()
    self.assertEqual(b, ['a', 'b', 'c'])
    a.remove('b')
    b = list(a)
    b.sort()
    self.assertEqual(b, ['a', 'c'])
    a.discard('d')
    b = set(['r', 's'])
    d = a.union(b)
    b = list(d)
    b.sort()
    self.assertEqual(b, ['a', 'c', 'r', 's'])
