Do you see a bus in this picture?
No, there are no buses.
    src        edge_attr  dst
0     0   to the left of    1
1     0   to the left of    4
2     0   to the left of    3
3     0   to the left of    6
4     1  to the right of    0
5     1   to the left of    3
6     2  to the right of    4
7     3  to the right of    1
8     3  to the right of    0
9     3               on    6
10    3  to the right of    4
11    4   to the left of    7
12    4   to the left of    5
13    4   to the left of    8
14    4  to the right of    0
15    4   to the left of    2
16    4   to the left of    3
17    5               on    6
18    5  to the right of    4
19    6  to the right of    0
20    7  to the right of    4
21    7               on    7
22    8  to the right of    4