What is the clock on?
The clock is on the post.
     src        edge_attr  dst
0      0  to the right of   19
1      0  to the right of   27
2      0  to the right of   23
3      0  to the right of   22
4      0  to the right of   18
..   ...              ...  ...
166   27  to the right of   11
167   27  to the right of   10
168   27   to the left of    0
169   27  to the right of   23
170   27   to the left of   26

[171 rows x 3 columns]