def test_tracestate_valid_pairs(self):
pairs = [("1a-2f@foo", "bar1"), ("foo-_*/bar", "bar4")]
state = TraceState(pairs)
self.assertEqual(len(state), 2)
self.assertIsNotNone(state.get("foo-_*/bar"))
self.assertEqual(state.get("foo-_*/bar"), "bar4")
self.assertEqual(state.to_header(), "1a-2f@foo=bar1,foo-_*/bar=bar4")
self.assertIsNone(state.get("random"))
def test_empty_tracestate(self):
state = TraceState()
self.assertEqual(len(state), 0)
self.assertEqual(state.to_header(), "")