What are the leaves on?
The leaves are on the tree.
    src        edge_attr  dst
0     0   to the left of   13
1     0  to the right of   15
2     1   to the left of   14
3     1   to the left of   13
4     1   to the left of    2
5     1   to the left of   12
6     1   to the left of    3
7     2  to the right of    3
8     2  to the right of    1
9     2  to the right of   14
10    3  to the right of    1
11    3  to the right of   14
12    3   to the left of    2
13    6               in    9
14    6          wearing   11
15    6         throwing   14
16    6          wearing    4
17    6          wearing    7
18    8          hitting   14
19    8          holding   15
20    8          wearing    5
21    8               in    9
22    8          wearing    0
23    8  to the right of   15
24    8   to the left of   14
25    8          wearing   10
26   12               on   13
27   12  to the right of    1
28   13  to the right of    0
29   13  to the right of    1
30   13  to the right of   14
31   14   to the left of    2
32   14  to the right of    1
33   14  to the right of    8
34   14   to the left of   13
35   14   to the left of    3
36   15   to the left of    0
37   15   to the left of    8