200   assert(strncmp (graph.object (3).head, "abc", 3) == 0);  in test_sort_kahn_1()
205   assert(strncmp (graph.object (2).head, "def", 3) == 0);  in test_sort_kahn_1()
209   assert(strncmp (graph.object (1).head, "jkl", 3) == 0);  in test_sort_kahn_1()
212   assert(strncmp (graph.object (0).head, "ghi", 3) == 0);  in test_sort_kahn_1()
229   assert(strncmp (graph.object (4).head, "abc", 3) == 0);  in test_sort_kahn_2()
235   assert(strncmp (graph.object (3).head, "def", 3) == 0);  in test_sort_kahn_2()
239   assert(strncmp (graph.object (2).head, "mn", 2) == 0);  in test_sort_kahn_2()
242   assert(strncmp (graph.object (1).head, "ghi", 3) == 0);  in test_sort_kahn_2()
246   assert(strncmp (graph.object (0).head, "jkl", 3) == 0);  in test_sort_kahn_2()
262   assert(strncmp (graph.object (4).head, "abc", 3) == 0);  in test_sort_shortest()
268   assert(strncmp (graph.object (3).head, "mn", 2) == 0);  in test_sort_shortest()
271   assert(strncmp (graph.object (2).head, "def", 3) == 0);  in test_sort_shortest()
275   assert(strncmp (graph.object (1).head, "ghi", 3) == 0);  in test_sort_shortest()
279   assert(strncmp (graph.object (0).head, "jkl", 3) == 0);  in test_sort_shortest()
295   assert(strncmp (graph.object (5).head, "abc", 3) == 0);  in test_duplicate_leaf()
301   assert(strncmp (graph.object (4).head, "jkl", 3) == 0);  in test_duplicate_leaf()
304   assert(strncmp (graph.object (3).head, "def", 3) == 0);  in test_duplicate_leaf()
308   assert(strncmp (graph.object (2).head, "ghi", 3) == 0);  in test_duplicate_leaf()
312   assert(strncmp (graph.object (1).head, "jkl", 3) == 0);  in test_duplicate_leaf()
315   assert(strncmp (graph.object (0).head, "mn", 2) == 0);  in test_duplicate_leaf()
331   assert(strncmp (graph.object (6).head, "abc", 3) == 0);  in test_duplicate_interior()
337   assert(strncmp (graph.object (5).head, "jkl", 3) == 0);  in test_duplicate_interior()
341   assert(strncmp (graph.object (4).head, "def", 3) == 0);  in test_duplicate_interior()
345   assert(strncmp (graph.object (3).head, "ghi", 3) == 0);  in test_duplicate_interior()
349   assert(strncmp (graph.object (2).head, "jkl", 3) == 0);  in test_duplicate_interior()
353   assert(strncmp (graph.object (1).head, "mn", 2) == 0);  in test_duplicate_interior()
356   assert(strncmp (graph.object (0).head, "opqrst", 6) == 0);  in test_duplicate_interior()