Is this a train or a bus?
This is a train.
    src        edge_attr  dst
0     0  to the right of   11
1     0  to the right of    2
2     0  to the right of    5
3     0  to the right of    3
4     2           behind    7
5     2   to the left of    0
6     2   to the left of    6
7     2   to the left of   11
8     3   to the left of    0
9     3  to the right of    5
10    5   to the left of    0
11    5   to the left of    3
12    6  to the right of    2
13    7      in front of    2
14    8  to the right of   12
15   11   to the left of    0
16   11  to the right of    2
17   11               on    9
18   12   to the left of    8