Are the trees in front of a fence?
No, the trees are behind a fence.
    src        edge_attr  dst
0     0   to the left of   18
1     0  to the right of   17
2     0  to the right of   19
3     0   to the left of    4
4     0  to the right of   13
..  ...              ...  ...
73   20   to the left of    2
74   20   to the left of    0
75   21               on   11
76   21  to the right of   15
77   21             near    2

[78 rows x 3 columns]