What vehicle is green?
The vehicle is a train.
    src        edge_attr  dst
0     3          next to   11
1     3             near   11
2     4  to the right of   13
3     4  to the right of   11
4     5  to the right of    7
5     6   to the left of    8
6     7   to the left of    5
7     8  to the right of    6
8     9  to the right of   12
9    11   to the left of    4
10   11             near    3
11   12   to the left of    9
12   13   to the left of    4