What is on the cage?
The fence is on the cage.
    src        edge_attr  dst
0     0   to the left of   19
1     0   to the left of    3
2     0  to the right of   21
3     2  to the right of    8
4     2  to the right of    4
..  ...              ...  ...
73   20   to the left of    4
74   20   to the left of    5
75   20   to the left of   15
76   20  to the right of   17
77   21   to the left of    0

[78 rows x 3 columns]