What is in the container?
The lettuce is in the container.
    src        edge_attr  dst
0     0   to the left of    3
1     1  to the right of    2
2     1  to the right of    3
3     2  to the right of    9
4     2   to the left of    5
5     2   to the left of    3
6     2   to the left of    7
7     2   to the left of    1
8     3  to the right of    2
9     3  to the right of    0
10    3   to the left of    1
11    3   to the left of    5
12    3  to the right of    9
13    5  to the right of    2
14    5  to the right of    3
15    5               in    0
16    7  to the right of    9
17    7  to the right of    2
18    8         lying on   10
19    9   to the left of    7
20    9   to the left of    3
21    9   to the left of    2