{"ast_node_type":"other","tokens":[{"end":39,"kind":"keyword","start":0,"text":"///"}]}
    /// you would get a `fn(u32, i32)`.
    /// and so forth -- so e.g., if we have a sig with `Fn<(u32, i32)>` then
    /// `unsafety` determines the unsafety of the fn signature. If you pass