Of what color is that envelope?
The envelope is green.
    src        edge_attr  dst
0     0  to the right of    1
1     0  to the right of    7
2     1   to the left of   13
3     1   to the left of   19
4     1   to the left of   14
..  ...              ...  ...
82   19  to the right of    5
83   19  to the right of    2
84   19  to the right of    7
85   19  to the right of   16
86   20  to the right of   15

[87 rows x 3 columns]