What is the clock on?
The clock is on the wall.
    src        edge_attr  dst
0     0   to the left of    5
1     0   to the left of   16
2     0            below   11
3     0   to the left of   15
4     0   to the left of   13
..  ...              ...  ...
75   19   to the left of   15
76   20   to the left of   16
77   20  to the right of    0
78   20  to the right of    4
79   20   to the left of   15

[80 rows x 3 columns]