The crosswalk has which color?
The crosswalk is white.
    src        edge_attr  dst
0     0               of    6
1     1               of   10
2     2   to the left of    7
3     6  to the right of   17
4     7  to the right of    2
5     8  to the right of   15
6     8         crossing    5
7     8   to the left of   12
8     9  to the right of   15
9     9   to the left of   13
10    9   to the left of   10
11   10  to the right of    9
12   10  to the right of   13
13   12  to the right of    8
14   13  to the right of    9
15   13  to the right of   15
16   13   to the left of   10
17   15   to the left of    9
18   15   to the left of   13
19   15   to the left of    8
20   17   to the left of    6