Is the sky dark or blue?
The sky is dark.
    src        edge_attr  dst
0     0               on    6
1     1   to the left of    5
2     1   to the left of    9
3     2               on    1
4     3  to the right of    7
5     4  to the right of    7
6     5  to the right of    7
7     5  to the right of    1
8     7   to the left of    9
9     7   to the left of    5
10    7   to the left of    4
11    7   to the left of    3
12    9  to the right of    1
13    9  to the right of    7