DiGraph: add dominators regression test

test/core/graph.py

@@ -16,3 +16,26 @@ print [x for x in g.predecessors('a')]
 print [x for x in g.predecessors('b')]
 print [x for x in g.predecessors('c')]
 print [x for x in g.successors('c')]
+
+
+"""
+Test from: https://en.wikipedia.org/wiki/Dominator_(graph_theory)
+"""
+
+g1 = DiGraph()
+g1.add_edge(1, 2)
+g1.add_edge(2, 3)
+g1.add_edge(2, 4)
+g1.add_edge(3, 5)
+g1.add_edge(4, 5)
+g1.add_edge(5, 2)
+g1.add_edge(2, 6)
+
+
+dominators = g1.compute_dominators()
+assert(dominators[1] == set([1]))
+assert(dominators[2] == set([1, 2]))
+assert(dominators[3] == set([1, 2, 3]))
+assert(dominators[4] == set([1, 2, 4]))
+assert(dominators[5] == set([1, 2, 5]))
+assert(dominators[6] == set([1, 2, 6]))