What is this, a bus or a train?
This is a train.
    src        edge_attr  dst
0     0  to the right of    8
1     0  to the right of   10
2     1  to the right of   10
3     1  to the right of    8
4     1               of    0
5     2   to the left of   10
6     2   to the left of   18
7     3   to the left of   12
8     4  to the right of    9
9     4  to the right of   18
10    5  to the right of   10
11    5  to the right of    8
12    6   to the left of    9
13    7   to the left of   15
14    8   to the left of    5
15    8   to the left of    0
16    8   to the left of    1
17    9  to the right of   14
18    9   to the left of    4
19    9   to the left of   16
20    9  to the right of    6
21   10   to the left of    1
22   10   to the left of    0
23   10  to the right of    2
24   10   to the left of    5
25   12  to the right of   13
26   12  to the right of    3
27   13   to the left of   12
28   14               of   13
29   14   to the left of    9
30   15  to the right of    7
31   16  to the right of   18
32   16  to the right of    9
33   18  to the right of    2
34   18   to the left of   16
35   18   to the left of    4