What is in front of the trees?
The barrier is in front of the trees.
     src        edge_attr  dst
0      0  to the right of   13
1      0  to the right of   24
2      0   to the left of    6
3      0   to the left of    2
4      0  to the right of   25
..   ...              ...  ...
132   26   to the left of    8
133   26  to the right of   12
134   26  to the right of   10
135   26   to the left of   22
136   26   to the left of   19

[137 rows x 3 columns]