pub trait ParentViewportWatcherProxyInterface: Send + Sync {
type GetLayoutResponseFut: Future<Output = Result<LayoutInfo, Error>> + Send;
type GetStatusResponseFut: Future<Output = Result<ParentViewportStatus, Error>> + Send;
// Required methods
fn get_layout(&self) -> Self::GetLayoutResponseFut;
fn get_status(&self) -> Self::GetStatusResponseFut;
}