What is common to the trunk and the fence?
The color, both the trunk and the fence are black.
    src        edge_attr  dst
0     0  to the right of    2
1     1   to the left of    2
2     1   to the left of    7
3     2   to the left of    8
4     2  to the right of    9
5     2   to the left of    0
6     2  to the right of    6
7     2  to the right of    1
8     5  to the right of    6
9     5  to the right of    9
10    5   to the left of    8
11    6   to the left of    7
12    6   to the left of    5
13    6   to the left of    2
14    7  to the right of    6
15    7  to the right of    1
16    7   to the left of    8
17    7  to the right of    9
18    8  to the right of    5
19    8  to the right of    2
20    8  to the right of    7
21    9   to the left of    7
22    9   to the left of    5
23    9   to the left of    2