What are the pipes on?
The pipes are on the motorcycle.
    src        edge_attr  dst
0     0   to the left of    6
1     0   to the left of    2
2     0   to the left of    4
3     2  to the right of    0
4     2  to the right of    4
5     4  to the right of    0
6     4   to the left of    2
7     4               on    8
8     5               on    8
9     5   to the left of   11
10    6  to the right of    0
11    7               of    8
12    8               on   12
13    8      in front of   10
14   11  to the right of    5