{"ast_node_type":"other","tokens":[{"end":88,"kind":"keyword","start":0,"text":"//"}]}
        // its return type, so we instead check for `<&Self as IntoIterator>::IntoIter`.
        // Checking for the existence of `iter()` is complicated in our setup, because we need to substitute
        // Does <&receiver_ty as IntoIterator>::IntoIter` exist? Assume `iter` is valid