What kind of vehicle is the helmet behind of?
The helmet is behind the car.
    src        edge_attr  dst
0     0   to the left of   14
1     0  to the right of   15
2     0   to the left of   10
3     0  to the right of   12
4     1   to the left of   15
5     1   to the left of   12
6     1   to the left of    4
7     1   to the left of    7
8     2  to the right of   11
9     2  to the right of    7
10    3   to the left of   17
11    3   to the left of    7
12    3   to the left of    5
13    4  to the right of    1
14    4   to the left of   12
15    4   to the left of    7
16    5  to the right of    3
17    5   to the left of    7
18    5   to the left of   17
19    7   to the left of    2
20    7  to the right of    4
21    7  to the right of    5
22    7  to the right of    3
23    7   to the left of   11
24    7  to the right of    1
25    8   to the left of   18
26    9      in front of   15
27   10  to the right of    0
28   10  to the right of   15
29   10  to the right of   16
30   11   to the left of    2
31   11  to the right of    7
32   11     parked along   10
33   12   to the left of    0
34   12  to the right of    4
35   12               in    9
36   12  to the right of    1
37   12   to the left of   15
38   13   on the side of   10
39   14  to the right of   15
40   14  to the right of   16
41   14  to the right of    0
42   15           behind    9
43   15   to the left of   10
44   15   to the left of   14
45   15   to the left of    0
46   15  to the right of    1
47   15  to the right of   12
48   16  to the right of   17
49   16   to the left of   14
50   16   to the left of   10
51   17  to the right of    5
52   17   to the left of   16
53   17  to the right of    3
54   18  to the right of    8
55   18   on the side of    6