1No vertices:
2directed: true
3vcount: 0
4edges: {
5}
6No edges, undirected:
7directed: false
8vcount: 10
9edges: {
10}
11Checking some basic outputs.
12Negative number of vertices.
13Negative number of edges.
14Exponent out too low.
15Exponent in too low but not negative.
16