Ok, just a test about propose on-chain, and then edit here.
expect chaos, lol

Set the new runtime code.

# <weight>
- `O(C + S)` where `C` length of `code` and `S` complexity of `can_set_code`
- 1 call to `can_set_code`: `O(S)` (calls `sp_io::misc::runtime_version` which is
  expensive).
- 1 storage write (codec `O(C)`).
- 1 digest item.
- 1 event.
The weight of this function is dependent on the runtime, but generally this is very
expensive. We will treat this as a full block.
# </weight>

#264 Proposali-98