What kind of furniture is to the left of the container that is made of glass?
The piece of furniture is a shelf.
    src        edge_attr  dst
0     0   to the left of    4
1     0   to the left of    1
2     0   to the left of   14
3     0   to the left of   13
4     1   to the left of   12
5     1  to the right of    0
6     3   to the left of   18
7     4  to the right of    6
8     4   to the left of    7
9     4   to the left of   21
10    4   to the left of   20
11    4   to the left of   10
12    4   to the left of    8
13    4   to the left of   19
14    4  to the right of    0
15    4   to the left of   18
16    6               on    0
17    6   to the left of    4
18    7  to the right of    4
19    7  to the right of   16
20    7               on   22
21    8  to the right of    4
22    8  to the right of   16
23   10  to the right of    4
24   11               on    5
25   11               on   17
26   12  to the right of    1
27   12  to the right of   13
28   12  to the right of   14
29   12   to the left of   21
30   12   to the left of   20
31   12   to the left of   19
32   13   to the left of   12
33   13  to the right of    0
34   14   to the left of   12
35   14  to the right of    0
36   16   to the left of    7
37   16   to the left of    8
38   17   to the left of   21
39   17   to the left of   20
40   18  to the right of    4
41   18  to the right of    3
42   19  to the right of   12
43   19  to the right of    4
44   20  to the right of   12
45   20  to the right of    4
46   20  to the right of   17
47   21  to the right of   12
48   21  to the right of   17
49   21  to the right of    4