What color do you think is the vehicle on the bridge?
The train is blue.
    src        edge_attr  dst
0     0          holding    8
1     0   to the left of    7
2     0   to the left of    5
3     1               of    4
4     2   to the left of    5
5     2   to the left of    7
6     4   to the left of    7
7     5               of   10
8     5  to the right of    8
9     5  to the right of    2
10    5  to the right of   11
11    5  to the right of    0
12    5   to the left of    7
13    6               on    9
14    6   to the left of    7
15    7  to the right of    6
16    7  to the right of    8
17    7  to the right of    4
18    7  to the right of    9
19    7  to the right of    5
20    7  to the right of   11
21    7  to the right of    0
22    7  to the right of    2
23    8   to the left of    5
24    8   to the left of    7
25    9               of   10
26    9   to the left of    7
27   10               on    9
28   11   to the left of    5
29   11   to the left of    7
30   11               of    0