public void testDefaultEdgePathOrientation() {
Graph g = new PrimaryGraph();
Node n1 = g.newNode();
Node n2 = g.newNode();
Edge e = g.newEdge(n1, n2);
Path p = e.asPath();
assertEquals(n1, p.headNode());
assertEquals(n2, p.tailNode());
}
public void testNegativeIndexInSingleEdge() {
Graph g = new PrimaryGraph();
Edge e = g.newEdge(g.newNode(), g.newNode());
assertSame(e.n2(), e.asPath().getNode(-1));
assertSame(e.n1(), e.asPath().getNode(-2));
}