Are there any clocks?
No, there are no clocks.
    src        edge_attr  dst
0     1   to the left of    2
1     1   to the left of    4
2     1   to the left of    5
3     2  to the right of    8
4     2  to the right of    1
5     4  to the right of    8
6     4  to the right of    1
7     5  to the right of    8
8     5  to the right of    1
9     7            below    8
10    8   to the left of   10
11    8   to the left of    2
12    8   to the left of    5
13    8   to the left of    4
14   10  to the right of    8