Do you see metal trains?
Yes, there is a train that is made of metal.
    src        edge_attr  dst
0     0   to the left of   10
1     0   to the left of    9
2     0   to the left of   11
3     2               at    3
4     5   to the left of   11
5     5             near    6
6     6   to the left of    9
7     6               at    3
8     6             near    5
9     7               at    3
10    9  to the right of   11
11    9  to the right of   10
12    9  to the right of    6
13    9  to the right of    0
14   10  to the right of    0
15   10   to the left of    9
16   10   to the left of   11
17   11  to the right of    0
18   11  to the right of    5
19   11   to the left of    9
20   11  to the right of   10