pub fn empty_fallback(mut self) -> Self {
        {
            self.fallback = Some(Arc::new(|cx, _| sycamore::view! { cx, }));
        }
        self
    }
Sets the fallback for this capsule to be an empty view.

You should be careful using this function in production, since it is
very often not what you actually want (especially since empty views
have no size, which may compromise your layouts: be sure to test
this).
packages/perseus/src/template/capsule.rs