def ClusteringCoefNodesDontExist_test():
G = Graph()
G.add_nodes_from(Friends)
G.add_edges_from(Relationships)
obs = G.clustering_coef(['Lexa', 'Roy', 'Demmi'])
exp = {}
assert_equal(exp, obs)
def clustCoefempty_test():
G = Graph()
G.add_nodes_from(Friends)
G.add_edges_from(Relationships)
# give an empty list
obs = G.clustering_coef(node_list=[])
exp = {}
assert_equal(exp, obs)