The forest is filled with what?
The forest is filled with trees.
    src        edge_attr  dst
0     1   to the left of   20
1     1   to the left of   16
2     1   to the left of    9
3     1   to the left of   14
4     1  to the right of   13
..  ...              ...  ...
65   26  to the right of    8
66   26  to the right of    1
67   26   to the left of    9
68   26   to the left of   14
69   26  to the right of   13

[70 rows x 3 columns]