What's in the box?
The tissue is in the box.
    src        edge_attr  dst
0     0   to the left of    5
1     0  to the right of    3
2     0  to the right of    9
3     2   to the left of   14
4     2               on    1
5     3   to the left of    6
6     3   to the left of    0
7     3   to the left of   12
8     3  to the right of   11
9     4  to the right of   10
10    4  to the right of    7
11    5  to the right of   14
12    5  to the right of    0
13    6  to the right of    9
14    6  to the right of    3
15    7   to the left of    4
16    7   to the left of   12
17    7   to the left of   17
18    9   to the left of    6
19    9   to the left of    0
20    9  to the right of   11
21   10   to the left of    4
22   11   to the left of    3
23   11   to the left of    9
24   11  to the right of   19
25   11  to the right of   18
26   12  to the right of    3
27   12  to the right of    7
28   14  to the right of   18
29   14               in    8
30   14  to the right of    2
31   14   to the left of    5
32   17               on    4
33   17  to the right of    7
34   18   to the left of   11
35   18   to the left of   14
36   19   to the left of   11
37   19               in    2