What is covered by the snow?
The trees are covered by the snow.
    src        edge_attr  dst
0     0               of    5
1     2               of    9
2     2  to the right of   10
3     2   to the left of    5
4     3   to the left of    5
5     3  to the right of   10
6     3               of    9
7     4       covered in   11
8     5  to the right of    2
9     5             near    9
10    5     covered with   11
11    5  to the right of   13
12    5  to the right of    3
13    5  to the right of    9
14    5       covered by   11
15    8  to the right of   10
16    9  to the right of   10
17    9               in   11
18    9   to the left of    5
19    9          next to    5
20   10   to the left of    2
21   10   to the left of    8
22   10   to the left of   12
23   10   to the left of    9
24   10   to the left of   13
25   10   to the left of    3
26   11               on    5
27   11               on    4
28   12  to the right of   10
29   13  to the right of   10
30   13   to the left of    5