testgraph_relations.txt

parent	child
1	2
1	3
4	2
4	3
5	6
7	6
8	9
8	10
11	9
11	10
12	13
14	13
15	16
15	17
15	18
15	19
2	16
2	17
2	18
2	19
16	20
16	21
17	22
17	23
17	24
10	22
10	23
10	24
18	25
6	25
19	26
19	27
19	28
13	26
13	27
13	28