What's on the field?
The fence is on the field.
    src        edge_attr  dst
0     0  to the right of    3
1     0  to the right of   16
2     0  to the right of   13
3     0  to the right of   18
4     0  to the right of    2
..  ...              ...  ...
71   22  to the right of   16
72   23  to the right of   19
73   26   to the left of   17
74   26   to the left of   21
75   26   to the left of    0

[76 rows x 3 columns]