What is in the bun that is in the bottom?
The sausage is in the bun.
    src        edge_attr  dst
0     0  to the right of    4
1     0  to the right of   13
2     0  to the right of    9
3     1  to the right of    7
4     4   to the left of    0
5     5               in    8
6     7               in    1
7     7   to the left of    1
8     9   to the left of    0
9    10  to the right of   12
10   12   to the left of   10
11   13   to the left of    0