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 left of   19
2     0  to the right of   16
3     0  to the right of   12
4     0  to the right of   11
5     0  to the right of   15
6     0  to the right of   14
7     1   to the left of    2
8     1  to the right of   17
9     2   to the left of    6
10    2   to the left of   10
11    2  to the right of    5
12    2   to the left of   19
13    2  to the right of   13
14    2   to the left of    7
15    2   to the left of   18
16    2  to the right of    3
17    2  to the right of    1
18    3   to the left of    2
19    3  to the right of   11
20    4               on    6
21    4   to the left of    0
22    5   to the left of    2
23    5   to the left of    6
24    5   to the left of    9
25    6  to the right of    2
26    6  to the right of    5
27    6   to the left of   18
28    7  to the right of    2
29    8               on   12
30    9  to the right of    5
31   10  to the right of    2
32   11   to the left of    0
33   11   to the left of   12
34   11   to the left of    3
35   11  to the right of   14
36   12  to the right of   11
37   12   to the left of    0
38   13   to the left of    2
39   13  to the right of   17
40   14               on   12
41   14   to the left of    0
42   14   to the left of   11
43   15               on   12
44   15   to the left of    0
45   16   to the left of    0
46   16               on   12
47   17   to the left of    1
48   17   to the left of   13
49   18  to the right of    2
50   18  to the right of    6
51   19  to the right of    0
52   19  to the right of    2