Which kind of vehicle is it?
The vehicle is a train.
   src        edge_attr  dst
0    0   to the left of    5
1    0  to the right of    2
2    0  to the right of    4
3    1  to the right of    4
4    2   to the left of    0
5    2  to the right of    8
6    4   to the left of    1
7    4   to the left of    0
8    5  to the right of    0
9    8   to the left of    2