What do the van and the rooftop have in common?
The color, both the van and the rooftop are red.
    src        edge_attr  dst
0     1            below    2
1     1             near    7
2     1  to the right of   12
3     1               on    3
4     1   to the left of   14
5     1   to the left of    6
6     2   to the left of    8
7     2   to the left of   11
8     4   to the left of   13
9     6   to the left of    9
10    6  to the right of   12
11    6  to the right of    1
12    6   to the left of   14
13    7               on    3
14    7             near    1
15    7            above    3
16    7  to the right of   12
17    8  to the right of    2
18    9  to the right of    6
19    9  to the right of   14
20   11  to the right of    2
21   12   to the left of    1
22   12   to the left of    7
23   12   to the left of    6
24   13  to the right of    4
25   14  to the right of    6
26   14  to the right of    1
27   14   to the left of    9