What is the bike on?
The bike is on the rock.
   src        edge_attr  dst
0    1           behind    3
1    1  to the right of    4
2    1   to the left of    2
3    2  to the right of    1
4    3               on    0
5    3      in front of    1
6    3  to the right of    4
7    4   to the left of    3
8    4   to the left of    1
9    5               of    3