How clean is that fork?
The fork is dirty.
    src        edge_attr  dst
0     1   to the left of    5
1     2  to the right of    3
2     2   to the left of    4
3     2   to the left of    5
4     2  to the right of    9
5     3   to the left of    2
6     3   to the left of   11
7     4  to the right of    2
8     5  to the right of    1
9     5  to the right of   11
10    5  to the right of    2
11    6  to the right of    9
12    6   to the left of   11
13    8   to the left of   12
14    8  to the right of    9
15    9   to the left of   11
16    9   to the left of    6
17    9   to the left of    2
18    9   to the left of    8
19   11  to the right of    6
20   11   to the left of    5
21   11  to the right of    9
22   11  to the right of    3
23   12  to the right of    8