Who is on the vehicle that the trees are behind of?
The people are on the train car.
    src        edge_attr  dst
0     0  to the right of   16
1     0               on   16
2     1          wearing    3
3     1  to the right of    9
4     1  to the right of   18
..  ...              ...  ...
77   17   on the side of    6
78   18   to the left of    3
79   18   to the left of    1
80   18  to the right of   11
81   18  to the right of   13

[82 rows x 3 columns]