+#! ./tesh
+
+$ $SG_TEST_EXENV ${bindir:=.}/graphxml_usage graph.xml
+> [0.000000] [test/INFO] ---- Testing XML export. Exporting to testgraph.xml ----
+> [0.000000] [test/INFO] ---- Testing GraphViz export. Exporting to testgraph.dot ----
+> [0.000000] [test/INFO] ---- Dumping Edge lengths ----
+> [0.000000] [test/INFO] 0.000000e+00 4.100000e-01 -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00
+> [0.000000] [test/INFO] -1.000000e+00 0.000000e+00 5.100000e-01 -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00
+> [0.000000] [test/INFO] -1.000000e+00 -1.000000e+00 0.000000e+00 5.000000e-01 -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00
+> [0.000000] [test/INFO] -1.000000e+00 -1.000000e+00 -1.000000e+00 0.000000e+00 -1.000000e+00 3.800000e-01 -1.000000e+00 -1.000000e+00
+> [0.000000] [test/INFO] -1.000000e+00 -1.000000e+00 -1.000000e+00 3.600000e-01 0.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00
+> [0.000000] [test/INFO] -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00 0.000000e+00 -1.000000e+00 -1.000000e+00
+> [0.000000] [test/INFO] -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00 3.800000e-01 -1.000000e+00 0.000000e+00 -1.000000e+00
+> [0.000000] [test/INFO] -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00 -1.000000e+00 0.000000e+00
+> [0.000000] [test/INFO] ---- Testing Shortest Paths ----
+> [0.000000] [test/INFO] A B B B B
+> [0.000000] [test/INFO] B C C C
+> [0.000000] [test/INFO] C D D
+> [0.000000] [test/INFO] D F
+> [0.000000] [test/INFO] D E D
+> [0.000000] [test/INFO] F
+> [0.000000] [test/INFO] E E E M
+> [0.000000] [test/INFO] P
+> [0.000000] [test/INFO] ---- Testing Topological Sort ----
+> [0.000000] [test/INFO] sorted[0] = P
+> [0.000000] [test/INFO] sorted[1] = M
+> [0.000000] [test/INFO] sorted[2] = E
+> [0.000000] [test/INFO] sorted[3] = A
+> [0.000000] [test/INFO] sorted[4] = B
+> [0.000000] [test/INFO] sorted[5] = C
+> [0.000000] [test/INFO] sorted[6] = D
+> [0.000000] [test/INFO] sorted[7] = F