Do you think the lock is gray?
Yes, the lock is gray.
    src        edge_attr  dst
0     0  to the right of    8
1     1   to the left of    9
2     4           behind    9
3     4  to the right of   11
4     7               on    5
5     7  to the right of   11
6     8   to the left of    0
7     9  to the right of    1
8     9      in front of    4
9    11   to the left of    7
10   11   to the left of    4