Do you see a silver fence there?
No, there is a fence but it is green.
    src        edge_attr  dst
0     0   to the left of    5
1     0   to the left of    6
2     0   to the left of    9
3     1   to the left of    3
4     2   to the left of    6
5     2   to the left of    4
6     3  to the right of    6
7     3  to the right of    5
8     3  to the right of   14
9     3  to the right of    9
10    3  to the right of   13
11    3  to the right of    1
12    4   to the left of    6
13    4  to the right of    2
14    5  to the right of    0
15    5   to the left of    3
16    5  to the right of   12
17    6   to the left of    3
18    6  to the right of    0
19    6  to the right of    4
20    6  to the right of   12
21    6  to the right of    2
22    9   to the left of    3
23    9  to the right of    0
24    9  to the right of   12
25   12   to the left of    9
26   12   to the left of    5
27   12   to the left of    6
28   13   to the left of    3
29   14   to the left of    3