tests/unit/vertex_selectors.out

Checking vs_none vertex selector:
Checking vector selector:
Some graph:
2
3
4
Edgeless graph:
2
3
4
Graph without vertices should fail.
Vertex selector with negative index should fail
Checking copy vector selector:
Some graph:
2
3
4
Edgeless graph:
2
3
4
Graph without vertices should fail.