What is the fence made of?
The fence is made of wood.
    src        edge_attr  dst
0     1           behind    6
1     1             near    6
2     1             near    4
3     1             near    2
4     1            below    2
5     1  to the right of    6
6     1   to the left of    5
7     2             near    1
8     2            above    1
9     2               on    4
10    3   to the left of    5
11    4             near    1
12    5  to the right of    3
13    5  to the right of    1
14    6      in front of    1
15    6   to the left of    1
16    6             near    1