What's in front of the trees?
The cars are in front of the trees.
    src        edge_attr  dst
0     1  to the right of    2
1     1  to the right of   10
2     1   to the left of    7
3     2   to the left of    7
4     2   to the left of    1
5     2      in front of    6
6     5  to the right of    7
7     5   to the left of    9
8     6           behind    2
9     6      in front of   13
10    6  to the right of   13
11    6  to the right of   11
12    6  to the right of   12
13    7  to the right of   10
14    7   to the left of    5
15    7   to the left of    9
16    7  to the right of    2
17    7  to the right of    1
18    9  to the right of   11
19    9  to the right of   13
20    9  to the right of   12
21    9  to the right of    7
22    9  to the right of    5
23   10   to the left of    1
24   10   to the left of    7
25   11   to the left of    9
26   11   to the left of    6
27   11   to the left of   13
28   12   to the left of    6
29   12   to the left of   13
30   12   to the left of    9
31   13           behind    6
32   13  to the right of   12
33   13   to the left of    9
34   13  to the right of   11
35   13   to the left of    6