Which kind of material is this fence made of?
The fence is made of plastic.
    src        edge_attr  dst
0     0   to the left of    2
1     2  to the right of    0
2     5  to the right of   13
3     5  to the right of    7
4     6  to the right of   11
5     6  to the right of   13
6     7   to the left of    5
7    11   to the left of    6
8    12          wearing   11
9    12          wearing    8
10   12          wearing    1
11   12          wearing    3
12   12          wearing    9
13   13   to the left of    6
14   13   to the left of    5