Do you see a fence or a skateboard?
Yes, there is a fence.
    src        edge_attr  dst
0     0  to the right of    8
1     0  to the right of    5
2     0  to the right of   11
3     1   to the left of    7
4     1   to the left of    6
5     2  to the right of    3
6     3   to the left of    2
7     4   to the left of    9
8     5   to the left of    0
9     6  to the right of    1
10    7        on top of    2
11    7  to the right of    1
12    8   to the left of    0
13    9  to the right of    4
14    9  to the right of   11
15   11   to the left of    0
16   11   to the left of   12
17   11   to the left of    9
18   12  to the right of   11