What vehicle is metallic?
The vehicle is a train.
    src        edge_attr  dst
0     0  to the right of    2
1     0   to the left of    3
2     0   to the left of    1
3     0  to the right of   13
4     0   to the left of   18
5     0   to the left of    5
6     0   to the left of   16
7     0   to the left of   14
8     0  to the right of   17
9     0  to the right of    9
10    0   to the left of    6
11    0          pulling   12
12    1   to the left of    6
13    1  to the right of    0
14    2   to the left of   12
15    2   to the left of    8
16    2   to the left of    0
17    3  to the right of    0
18    4  to the right of   12
19    4   to the left of   16
20    4   to the left of    6
21    5  to the right of    0
22    5   to the left of    6
23    6  to the right of    1
24    6  to the right of    0
25    6  to the right of    5
26    6  to the right of    4
27    6  to the right of   16
28    8  to the right of    2
29    8  to the right of   17
30    9   to the left of    0
31    9   to the left of   12
32   12  to the right of    2
33   12  to the right of    9
34   12   to the left of    4
35   12  to the right of   13
36   12        pulled by    0
37   13   to the left of   12
38   13   to the left of    0
39   14  to the right of    0
40   16  to the right of    0
41   16   to the left of   18
42   16  to the right of    4
43   16   to the left of    6
44   17   to the left of    0
45   17   to the left of    8
46   18        on top of    6
47   18  to the right of    0
48   18  to the right of   16