What is covered in the snow?
The trees are covered in snow.
    src        edge_attr  dst
0     0      standing in    5
1     0          wearing    1
2     0             near    2
3     0   to the left of    5
4     0  to the right of    2
5     0          next to    2
6     0          wearing    6
7     1   to the left of    5
8     1  to the right of    2
9     2   to the left of    1
10    2   to the left of    0
11    2   to the left of    6
12    2   to the left of    4
13    2             near    0
14    3       covered in    5
15    4  to the right of    2
16    5  to the right of    1
17    5  to the right of    0
18    6  to the right of    2