Which color is the pine tree in front of the pine, brown or green?
The pine tree is brown.
    src        edge_attr  dst
0     0   to the left of    7
1     2               of    6
2     6           behind    9
3     6      in front of    6
4     6           behind    6
5     7               of    9
6     7  to the right of    0
7     8               on    9
8     9               on    7
9     9      in front of    6
10    9       mounted to    7