What color do you think the fence that is on the side walk is?
The fence is black.
    src        edge_attr  dst
0     1  to the right of    5
1     1   to the left of    3
2     2  to the right of    9
3     2   to the left of   10
4     3  to the right of    1
5     4   to the left of   10
6     4               on    0
7     5   to the left of    6
8     5   to the left of    1
9     6  to the right of    5
10    7   to the left of   13
11    7   to the left of   11
12    8   to the left of   11
13    9   to the left of    2
14    9   to the left of   10
15   10  to the right of    4
16   10  to the right of    2
17   10  to the right of    9
18   11  to the right of    7
19   11  to the right of    8
20   12               on   14
21   13  to the right of    7