What material is the sidewalk made of?
The sidewalk is made of cement.
     src        edge_attr  dst
0      0  to the right of   16
1      0  to the right of   14
2      0  to the right of   34
3      0  to the right of   29
4      0  to the right of   15
..   ...              ...  ...
243   34   to the left of   33
244   34   to the left of   31
245   34   to the left of   13
246   34   to the left of   16
247   34  to the right of   26

[248 rows x 3 columns]