What's the snow covering?
The snow is covering the tree.
    src        edge_attr  dst
0     0  to the right of    6
1     1  to the right of   12
2     1   to the left of   20
3     2  to the right of   11
4     3         covering    7
5     3               on    4
6     3               on    7
7     4  to the right of    7
8     6   to the left of    0
9     6  to the right of   12
10    6               of    8
11    6   to the left of   15
12    7       covered by    3
13    7   to the left of    4
14    7           behind    8
15    8          wearing    9
16    8          holding   12
17    8          wearing    5
18    8      in front of    7
19    8          wearing   17
20    8          holding   20
21    8          wearing    1
22    8          wearing    0
23    8   to the left of   20
24    8  to the right of   12
25    9   to the left of   20
26    9   to the left of   14
27   11   to the left of    2
28   12   to the left of    1
29   12   to the left of    6
30   12   to the left of    8
31   14  to the right of    9
32   15  to the right of    6
33   18               on   19
34   20  to the right of    1
35   20  to the right of    9
36   20  to the right of    8