What is common to the canopy and the arrow?
The color, both the canopy and the arrow are black.
    src        edge_attr  dst
0     0   to the left of   15
1     0   to the left of    8
2     1  to the right of    2
3     1  to the right of   15
4     1  to the right of    8
..  ...              ...  ...
82   20   to the left of    5
83   20  to the right of   19
84   20   to the left of    8
85   21  to the right of   18
86   21  to the right of   15

[87 rows x 3 columns]