What animal is to the right of the cow?
The animal is a zebra.
   src        edge_attr  dst
0    0               by    4
1    1   to the left of    2
2    1   to the left of    3
3    2  to the right of    1
4    2   to the left of    3
5    3               by    1
6    3  to the right of    1
7    3  to the right of    2