What is in front of the wall?
The building is in front of the wall.
    src        edge_attr  dst
0     0   to the left of   11
1     0   to the left of    4
2     0   to the left of   13
3     0   to the left of   12
4     2        on top of   16
5     4            above   13
6     4               on   15
7     4  to the right of   14
8     4  to the right of   19
9     4  to the right of   20
10    4  to the right of    0
11    6   to the left of   18
12    6   to the left of   17
13    6   to the left of    8
14    7  to the right of   21
15    8           around   15
16    8   to the left of   17
17    8  to the right of   15
18    8  to the right of    6
19    8   to the left of   18
20    9           behind   15
21   10        on top of   15
22   11  to the right of    0
23   12            under   20
24   12            below   20
25   12  to the right of    0
26   13            under    4
27   13  to the right of    0
28   14   to the left of    4
29   15             with   20
30   15      in front of    9
31   15             with    4
32   15   to the left of    8
33   15   to the left of   18
34   15   to the left of   17
35   17  to the right of    8
36   17  to the right of    6
37   17  to the right of   18
38   17  to the right of   15
39   18  to the right of    8
40   18  to the right of   15
41   18  to the right of    6
42   18   to the left of   17
43   19   to the left of    4
44   20            below   21
45   20               on   15
46   20            above   12
47   20   to the left of    4
48   21            above   20
49   21   to the left of    7