'Betweenness centrality: P4'

def test_P4(self):

    G = nx.path_graph(4)
    b = nx.current_flow_betweenness_centrality(G, normalized=False)
    b_answer = {0: 0, 1: 2, 2: 2, 3: 0}
    for n in sorted(G):
        assert_almost_equal(b[n], b_answer[n])
