What is in front of the green tree?
The fence is in front of the tree.
    src        edge_attr  dst
0     0      in front of   19
1     0      in front of    4
2     0      in front of    9
3     1  to the right of   17
4     1   to the left of    6
..  ...              ...  ...
85   19  to the right of    5
86   19   to the left of    3
87   19   to the left of   10
88   20   to the left of    1
89   20  to the right of    9

[90 rows x 3 columns]