adding a test for a DAG where a node is visited twice
adding a test for a DAG where a node is visited twice

thomaskrause/graphANNIS,thomaskrause/graphANNIS,thomaskrause/graphANNIS,thomaskrause/graphANNIS,thomaskrause/graphANNIS,thomaskrause/graphANNIS,thomaskrause/graphANNIS