What kind of sign is on the wire?
The sign is a stop sign.
    src        edge_attr  dst
0     0   to the left of   16
1     0  to the right of    5
2     2               in   12
3     2   to the left of   16
4     2   to the left of   14
5     2  to the right of    5
6     3   to the left of    7
7     3   to the left of    9
8     4  to the right of   10
9     4  to the right of    5
10    4  to the right of   11
11    5   to the left of    0
12    5               in   12
13    5   to the left of    4
14    5   to the left of    2
15    6  to the right of   10
16    6  to the right of   13
17    6               in   12
18    6  to the right of   11
19    6   to the left of    9
20    7  to the right of    3
21    7  to the right of    8
22    7  to the right of   13
23    7               in   12
24    8               in   12
25    8   to the left of    7
26    8  to the right of   15
27    9  to the right of   16
28    9  to the right of    3
29    9  to the right of    6
30   10   to the left of   16
31   10  to the right of   11
32   10   to the left of   13
33   10   to the left of    4
34   10   to the left of   14
35   10   to the left of    6
36   10               in   12
37   11               on    3
38   11   to the left of   10
39   11   to the left of   13
40   11   to the left of    6
41   11   to the left of    4
42   13  to the right of   11
43   13   to the left of    6
44   13   to the left of   14
45   13   to the left of   16
46   13  to the right of   10
47   13   to the left of    7
48   14  to the right of    2
49   14  to the right of   10
50   14  to the right of   13
51   15   to the left of    8
52   16  to the right of    0
53   16  to the right of    2
54   16   to the left of    9
55   16  to the right of   13
56   16  to the right of   10