What type of material is the fence that looks blue made of?
The fence is made of metal.
     src       edge_attr  dst
0      0  to the left of   23
1      0  to the left of    5
2      0  to the left of    8
3      0  to the left of    7
4      1          behind   17
..   ...             ...  ...
234   34      leaning on   17
235   34  to the left of    3
236   34  to the left of   26
237   34  to the left of    4
238   34  to the left of   15

[239 rows x 3 columns]