pub trait PreviewGenerator {
// Required method
fn generate_preview<'life0, 'life1, 'async_trait>(
&'life0 self,
url: &'life1 str,
) -> Pin<Box<dyn Future<Output = Result<Preview, PreviewError>> + Send + 'async_trait>>
where Self: 'async_trait,
'life0: 'async_trait,
'life1: 'async_trait;
}