1No vertices:
2Mutual: 0 asymmetric: 0 null: 0
3
4One vertex:
5Mutual: 0 asymmetric: 0 null: 0
6
7Two vertices:
8Mutual: 0 asymmetric: 1 null: 0
9
10Graph with loops and multiple edges:
11Mutual: 1 asymmetric: 4 null: 10
12
13Same graph, but undirected:
14Mutual: 5 asymmetric: 0 null: 10
15
16