{"ast_node_type":"other","tokens":[{"end":37,"kind":"keyword","start":0,"text":"Ref(&'hir"}]}
    Ref(&'hir Lifetime, MutTy<'hir>),
    /// A reference (i.e., `&'a T` or `&'a mut T`).
    /// A function pointer (e.g., `fn(usize) -> bool`).