Are there any fences behind the trees?
Yes, there is a fence behind the trees.
     src        edge_attr  dst
0      0            below    1
1      0   to the left of   15
2      0   to the left of   13
3      0  to the right of   33
4      0   to the left of   19
..   ...              ...  ...
146   34             near   35
147   34             near   13
148   34           behind   22
149   35             near   34
150   36  to the right of    8

[151 rows x 3 columns]