What is the bench made of?
The bench is made of metal.
    src        edge_attr  dst
0     1  to the right of    6
1     2  to the right of   13
2     2             near   14
3     2  to the right of   15
4     6   to the left of    1
5     7  to the right of   13
6     7  to the right of   15
7     8   to the left of   10
8     8  to the right of   15
9     9  to the right of   12
10   10  to the right of   15
11   10  to the right of    8
12   12   to the left of    9
13   13   to the left of    2
14   13   to the left of    7
15   14               on   12
16   14          next to    2
17   14             near    2
18   15   to the left of    7
19   15   to the left of   10
20   15   to the left of    8
21   15   to the left of    2