HasInitialized: StorageDescriptor<[], undefined, true>

Whether the parachains modules have been initialized within this block.

Semantically a bool, but this guarantees it should never hit the trie, as this is cleared in on_finalize and Frame optimizes None values to be empty values.

As a bool, set(false) and remove() both lead to the next get() being false, but one of them writes to the trie and one does not. This confusion makes Option<()> more suitable for the semantics of this variable.