What is the glass vehicle?
The vehicle is a bus.
    src        edge_attr  dst
0     0   to the left of    5
1     0   to the left of    2
2     0  to the right of    8
3     2  to the right of    8
4     2  to the right of    3
5     2   to the left of    9
6     2  to the right of    0
7     3   to the left of    7
8     3   to the left of    2
9     3   to the left of    5
10    3   to the left of    4
11    4  to the right of    3
12    4  to the right of    7
13    5  to the right of    0
14    5  to the right of    8
15    5  to the right of    3
16    7   to the left of    4
17    7  to the right of    3
18    8   to the left of    0
19    8   to the left of    2
20    8   to the left of    5
21    9  to the right of    2