What type of vehicle is electronic?
The vehicle is a train.
    src        edge_attr  dst
0     0   to the left of    4
1     0   to the left of    1
2     1  to the right of    7
3     1  to the right of    0
4     1  to the right of    6
5     2   to the left of    4
6     2  to the right of    6
7     3  to the right of    6
8     4  to the right of    2
9     4  to the right of    0
10    4  to the right of    6
11    6   to the left of    3
12    6   to the left of    2
13    6   to the left of    1
14    6   to the left of    4
15    6         boarding    1
16    6               in    5
17    7               on    0
18    7  to the right of    8
19    7   to the left of    1
20    8   to the left of    7