Which place is it?
It is a field.
   src        edge_attr  dst
0    0   to the left of    2
1    0   to the left of   13
2    2  to the right of    0
3    4  to the right of    9
4    8   to the left of   11
5    9   to the left of    4
6   11  to the right of    8
7   13               of    2
8   13  to the right of    0