def test_graph_get_nodes():
grappy = Graph()
vert_1 = grappy.add_vertex('A')
vert_2 = grappy.add_vertex('B')
actual = str(grappy.get_nodes())
expected = f'dict_keys({[vert_1, vert_2]})'
assert actual == expected
def test_add_node2():
graph = Graph()
graph.add_node("spam")
actual = graph.get_nodes()
expected = 1
assert len(actual) == expected
assert isinstance(actual[0], Vertex)
assert actual[0].value == "spam"
def test_get_nodes():
graph = Graph()
graph.add_node("banana")
graph.add_node("apple")
expected = 2
actual = len(graph.get_nodes())
assert actual == expected
def test_get_nodes():
g = Graph()
g.add_node("spam")
g.add_node("eggs")
actual = g.get_nodes()
expected = 2
assert len(actual) == expected
assert isinstance(actual[0], Vertex)
assert isinstance(actual[1], Vertex)
assert actual[0].value == "spam"
assert actual[1].value == "eggs"
