What is the fence made of?
The fence is made of metal.
    src        edge_attr  dst
0     0   flying through    5
1     0               in    4
2     1  to the right of   13
3     1   to the left of    3
4     3  to the right of   15
5     3  to the right of    1
6     8   to the left of   14
7    13   to the left of    1
8    13   to the left of   15
9    13   to the left of   14
10   14               on    2
11   14  to the right of   13
12   14  to the right of    8
13   15  to the right of   13
14   15   to the left of    3