Does the sky have blue color?
No, the sky is dark.
    src        edge_attr  dst
0     1   to the left of    2
1     2  to the right of    1
2     3   to the left of    5
3     4               on    7
4     4   to the left of    9
5     5  to the right of    3
6     6   to the left of   10
7     7               on    6
8     7   to the left of   10
9     9  to the right of    4
10   10  to the right of    6
11   10  to the right of    7