Are there any cows?
No, there are no cows.
    src       edge_attr  dst
0     1  to the left of   13
1     1  to the left of   15
2     1  to the left of    9
3     3  to the left of   10
4     3  to the left of   15
..  ...             ...  ...
67   19  to the left of   15
68   19  to the left of   16
69   19  to the left of    8
70   19  to the left of   17
71   19  to the left of    4

[72 rows x 3 columns]