The fence is in front of what?
The fence is in front of the tree.
   src        edge_attr  dst
0    0               in   10
1    0           behind    2
2    0   to the left of   11
3    1           flying    5
4    1               in   10
5    2      in front of    0
6    5               in    7
7   11  to the right of    0