Is this a bus or a truck?
This is a bus.
    src        edge_attr  dst
0     1  to the right of    6
1     2  to the right of    3
2     2  to the right of    6
3     3   to the left of    8
4     3   to the left of    6
5     3   to the left of    2
6     4   to the left of    5
7     5  to the right of    4
8     6   to the left of    8
9     6   on the side of    0
10    6  to the right of    3
11    6   to the left of    2
12    6   to the left of    1
13    8  to the right of    3
14    8  to the right of    6