Do you see any low benches in the image?
Yes, there is a low bench.
    src        edge_attr  dst
0     0  to the right of    6
1     0   to the left of   10
2     0  to the right of    3
3     0  to the right of    5
4     1   to the left of   11
5     1   to the left of   10
6     1  to the right of    4
7     2  to the right of    4
8     3   to the left of    0
9     4   to the left of    2
10    4   to the left of    1
11    5   to the left of    0
12    5   to the left of    6
13    6  to the right of    5
14    6   to the left of    0
15   10  to the right of    0
16   10  to the right of    1
17   10               on   11
18   11  to the right of    1