What are the leaves on?
The leaves are on the branch.
    src        edge_attr  dst
0     0  to the right of   28
1     0               of   25
2     0  to the right of    7
3     0  to the right of   27
4     1  to the right of   28
..  ...              ...  ...
77   28   to the left of    1
78   28               on   27
79   29           behind   25
80   29   to the left of   25
81   29   to the left of   21

[82 rows x 3 columns]