Function wait_for_code 

fn wait_for_code(
    sign_in: &SignIn,
    deadline: Duration,
    stop: &AtomicBool,
    personal: Option<bool>,
) -> Result<String, SyncError>

The answer Microsoft’s page sends back to this device: its code, checked against the state. An answer whose state is not this sign-in’s is refused, and the wait goes on: a page from an earlier sign-in, or anyone else, cannot end it. An error is read only from an answer whose state is.