What are the buildings in front of?
The buildings are in front of the tree.
   src        edge_attr  dst
0    0   to the left of    2
1    1           behind    3
2    1   to the left of    2
3    2             near    5
4    2  to the right of    1
5    2  to the right of    0
6    3      in front of    1
7    5             near    2