Are there either plates or forks that are made of metal?
Yes, the plate is made of metal.
     src        edge_attr  dst
0      0   to the left of   21
1      0   to the left of   20
2      0   to the left of    4
3      0   to the left of    6
4      0   to the left of    5
..   ...              ...  ...
138   21  to the right of    0
139   21   to the left of   13
140   21   to the left of   11
141   22   to the left of    5
142   22   to the left of    6

[143 rows x 3 columns]