Is the tray on the right of the picture?
Yes, the tray is on the right of the image.
   src        edge_attr  dst
0    1  to the right of    8
1    2               on    7
2    2   to the left of    5
3    2   to the left of    4
4    4  to the right of    2
5    5               on    4
6    5  to the right of    2
7    6  to the right of    8
8    8   to the left of    6
9    8   to the left of    1