What is the vehicle that is in front of the tree?
The vehicle is a bus.
    src        edge_attr  dst
0     0      in front of   10
1     0        parked on    1
2     0   to the left of    6
3     0  to the right of    4
4     0   to the left of    8
5     0  to the right of    5
6     2  to the right of    4
7     2   to the left of   11
8     2  to the right of    5
9     3   to the left of    7
10    3  to the right of    4
11    3   to the left of    9
12    4   to the left of    0
13    4   to the left of    3
14    4   to the left of    2
15    4   to the left of   14
16    5   to the left of   11
17    5   to the left of    0
18    5   to the left of    2
19    6  to the right of    0
20    7  to the right of    9
21    7   on the side of    0
22    7  to the right of   14
23    7  to the right of    3
24    8  to the right of    0
25    8        parked on    1
26    9   to the left of    7
27    9  to the right of    3
28    9  to the right of   14
29   10           behind    0
30   11  to the right of    2
31   11   to the left of   12
32   11  to the right of    5
33   12  to the right of   11
34   14  to the right of    4
35   14          driving    0
36   14   to the left of    7
37   14   to the left of    9