def test_construction_from_node_and_type_arguments(self):
rel = Relationship(alice, "LIKES")
assert rel.start_node() is alice
assert rel.end_node() is alice
assert rel.type() == "LIKES"
def test_construction_from_three_arguments(self):
rel = Relationship(alice, "KNOWS", bob)
assert rel.start_node() is alice
assert rel.end_node() is bob
assert rel.type() == "KNOWS"
def test_construction_from_one_argument(self):
rel = Relationship(alice)
assert rel.start_node() is alice
assert rel.end_node() is alice
assert rel.type() == "TO"