What animal is walking in the grassy field?
The animal is a bull.
    src        edge_attr  dst
0     2   to the left of   19
1     2   to the left of   18
2     2  to the right of   10
3     2               of    7
4     3               of    7
5     4  to the right of   19
6     7       walking in   12
7     7               in   12
8     7      in front of   13
9     8               in    6
10    8               in   12
11   10               of    7
12   10   to the left of    2
13   13           behind    7
14   14           behind   15
15   15  to the right of   17
16   15      in front of   14
17   17   to the left of   15
18   18               of    7
19   18  to the right of    2
20   19  to the right of    2
21   19               of    7
22   19   to the left of    4