def test_DAG_get_v_structures(test_dag, reversed_dag, partial_dag):
dag = test_dag
assert partial_dag.get_v_structures() == {("C", "B", "D")}
assert dag.get_v_structures() == set()
assert dag.get_v_structures(True) == {("C", "B", "D")}
assert reversed_dag.get_v_structures(True) == {("B", "D", "C")}
# Test node order doesn't change V-structure tuple order
other_dag = DAG()
other_dag.add_vertices(list("DCBA"))
other_dag.add_edges([("C", "B"), ("D", "B"), ("D", "C")])
assert other_dag.get_v_structures(True) == dag.get_v_structures(True)
def test_compare(temp_out, test_dag):
img_path = temp_out / 'comparison.png'
dag2 = DAG()
dag2.add_vertices(list("ABCD"))
comparison_1 = test_dag.compare(dag2)
assert comparison_1.es['color'] == ['red'] * 3
assert comparison_1.es['style'] == ['dashed'] * 3
comparison_2 = dag2.compare(test_dag)
assert comparison_2.es['color'] == ['blue'] * 3
assert comparison_2.es['style'] == ['solid'] * 3
comparison_1.plot(img_path)
assert img_path.exists()
