pub trait Command: Send + Sync {
// Required method
fn start<'life0, 'life1, 'async_trait>(
&'life0 self,
payload: Cow<'life1, str>,
callback: Box<CallbackFn>,
) -> Pin<Box<dyn Future<Output = ()> + 'async_trait>>
where Self: 'async_trait,
'life0: 'async_trait,
'life1: 'async_trait;
// Provided method
fn describe_ha(&self) -> Option<Discovery> { ... }
}