Is this a bus or a train?
This is a bus.
    src        edge_attr  dst
0     0  to the right of    5
1     1  to the right of    5
2     2               of    7
3     2   to the left of    3
4     2   to the left of    5
5     2  to the right of    6
6     3  to the right of    2
7     3   to the left of    5
8     3  to the right of    6
9     4  to the right of    5
10    5  to the right of    3
11    5   to the left of    4
12    5   to the left of    8
13    5  to the right of    7
14    5   to the left of    0
15    5   to the left of    1
16    5  to the right of    2
17    6   to the left of    7
18    6   to the left of    3
19    6   to the left of    2
20    7   to the left of    5
21    7  to the right of    6
22    8  to the right of    5