1No vertices:
2
3No edges:
4        0        0        0
5        0        0        0
6        0        0        0
7
8Disconnected graph with loops and multiple edges:
9        0        1        1        0        0        0
10        0        1        0        1        0        0
11        1        0        0        1        0        0
12        0        0        0        0        2        0
13        0        0        0        0        0        0
14        0        0        0        0        0        0
15
16Same graph, undirected, symmetric matrix:
17        0        1        2        0        0        0
18        1        1        0        1        0        0
19        2        0        0        1        0        0
20        0        1        1        0        2        0
21        0        0        0        2        0        0
22        0        0        0        0        0        0
23
24Same graph, undirected, upper triangular matrix:
25        0        1        2        0        0        0
26        0        1        0        1        0        0
27        0        0        0        1        0        0
28        0        0        0        0        2        0
29        0        0        0        0        0        0
30        0        0        0        0        0        0
31
32Same graph, undirected, lower triangular matrix:
33        0        0        0        0        0        0
34        1        1        0        0        0        0
35        2        0        0        0        0        0
36        0        1        1        0        0        0
37        0        0        0        2        0        0
38        0        0        0        0        0        0
39
40