What is the vehicle that this airplane is in front of?
The vehicle is a van.
    src        edge_attr  dst
0     1               on   17
1     1   to the left of    7
2     1   to the left of   14
3     2           behind   15
4     2      in front of    8
5     2               on   17
6     4  to the right of   16
7     5  to the right of   10
8     5   to the left of   11
9     6               on   17
10    6            below   15
11    6             near   15
12    6            under   15
13    7  to the right of    1
14    7   to the left of   14
15    8           behind    2
16    8           behind   15
17    8   to the left of   16
18    9  to the right of   10
19    9  to the right of   16
20    9   to the left of   11
21   10   to the left of    5
22   10   to the left of    9
23   11  to the right of    5
24   11  to the right of    9
25   12           behind   15
26   14  to the right of    7
27   14  to the right of    1
28   15      in front of    2
29   15               at   17
30   15               on   17
31   15            above    6
32   15             near    6
33   15      in front of    8
34   16   to the left of    4
35   16   to the left of    9
36   16  to the right of    8