{"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"///"}]}
    /// expression `Some(&[1, 2, 3])`, and that has the expected type
    /// basically `for<T> fn(T) -> Option<T>`. So if we have an
    /// `Option<&[u32]>`, we would like to type check `&[1, 2, 3]`