Is this a train or a bus?
This is a bus.
    src        edge_attr  dst
0     0  to the right of    4
1     0  to the right of    1
2     1               of    7
3     1   to the left of    4
4     1   to the left of    0
5     2  to the right of   17
6     3   to the left of   21
7     3   to the left of    7
8     4   to the left of    0
9     4  to the right of    1
10    5   to the left of   10
11    5   to the left of    7
12    6               on    9
13    7  to the right of   10
14    7  to the right of   18
15    7  to the right of    8
16    7  to the right of    3
17    7  to the right of    5
18    8   to the left of    7
19    8   to the left of   15
20   10  to the right of    5
21   10   to the left of    7
22   14   to the left of   17
23   14   to the left of   20
24   15               on   14
25   15   to the left of   20
26   15  to the right of   18
27   15  to the right of    8
28   17   to the left of    2
29   17  to the right of   14
30   18          wearing    8
31   18   to the left of    7
32   18   to the left of   15
33   18   to the left of   20
34   18               by   14
35   20               on   17
36   20  to the right of   14
37   20  to the right of   18
38   20  to the right of   15
39   21  to the right of    3