What is the tree covered in?
The tree is covered in leaves.
    src        edge_attr  dst
0     0  to the right of    8
1     1   to the left of   17
2     1   to the left of   21
3     1  to the right of   18
4     1   to the left of   12
..  ...              ...  ...
83   21  to the right of    8
84   21               of   12
85   21  to the right of   17
86   22   to the left of   13
87   22   to the left of   16

[88 rows x 3 columns]