What device is portable?
The device is a keyboard.
    src        edge_attr  dst
0     0  to the right of   13
1     0  to the right of   17
2     1  to the right of   15
3     2  to the right of   18
4     2  to the right of   10
5     2  to the right of    9
6     4  to the right of    8
7     6  to the right of   12
8     7  to the right of   19
9     8   to the left of    4
10    9  to the right of   10
11    9   to the left of    2
12    9   to the left of   18
13   10   to the left of    9
14   10   to the left of    2
15   10   to the left of   18
16   12   to the left of    6
17   13   to the left of    0
18   13   to the left of   17
19   15   to the left of    1
20   17   to the left of    0
21   17  to the right of   13
22   18  to the right of    9
23   18  to the right of   10
24   18   to the left of    2
25   19   to the left of    7