Are there either any serving trays or mailboxes?
No, there are no mailboxes or serving trays.
     src        edge_attr  dst
0      0  to the right of   33
1      0   to the left of   29
2      1   to the left of    7
3      1   to the left of   31
4      1  to the right of    9
..   ...              ...  ...
130   37  to the right of   23
131   38  to the right of   19
132   38  to the right of   17
133   38  to the right of   10
134   38  to the right of   35

[135 rows x 3 columns]