Is the gray terminal made of steel?
Yes, the terminal is made of steel.
    src        edge_attr  dst
0     0   to the left of    5
1     1            below    8
2     1   to the left of    9
3     3      in front of    6
4     3   to the left of    5
5     5  to the right of    9
6     5            below    8
7     5  to the right of    0
8     5  to the right of    3
9     5  to the right of    6
10    5  to the right of    7
11    6   to the left of    5
12    6   to the left of   10
13    6            below    8
14    7            below    8
15    7   to the left of    5
16    9  to the right of    1
17    9   to the left of    5
18   10  to the right of    6