Are there any glasses or fences in the scene?
Yes, there is a fence.
    src        edge_attr  dst
0     1   to the left of   13
1     1  to the right of   16
2     1  to the right of   18
3     1   to the left of    5
4     1  to the right of    3
..  ...              ...  ...
69   19  to the right of    2
70   19  to the right of   18
71   19  to the right of   16
72   19   to the left of   13
73   19   to the left of   12

[74 rows x 3 columns]