pub trait IntlProxyInterface: Send + Sync {
type WatchResponseFut: Future<Output = Result<IntlSettings, Error>> + Send;
type SetResponseFut: Future<Output = Result<IntlSetResult, Error>> + Send;
// Required methods
fn watch(&self) -> Self::WatchResponseFut;
fn set(&self, settings: &IntlSettings) -> Self::SetResponseFut;
}