What's the room covered by?
The room is covered by the ceiling.
    src        edge_attr  dst
0     0       covered by    2
1     3   to the left of   18
2     3   to the left of   17
3     3   to the left of   22
4     3   to the left of    9
..  ...              ...  ...
70   24   to the left of   22
71   24  to the right of    7
72   24  to the right of   23
73   25  to the right of   20
74   25  to the right of   19

[75 rows x 3 columns]