Function assert_my_externref

tests/all/func.rs:1612–1622

(store: impl AsContext, externref: Option<Rooted<ExternRef>>)

        Ok(())
    }
    fn assert_my_externref(store: impl AsContext, externref: Option<Rooted<ExternRef>>) {
        assert_eq!(
            externref
                .unwrap()
                .data(&store)
                .unwrap()
                .unwrap()
                .downcast_ref(),
            Some(&99u32)
        );
    }

    // funcref=null, externref=null
    let (a, b) = typed.call(&mut store, (None, None))?;