{"ast_node_type":"variable","tokens":[{"end":40,"kind":"keyword","start":0,"text":"let"}]}
        let ty_u8 = self.cx.ty_path(u8);
        let u8 = self.cx.path_ident(self.span, Ident::new(sym::u8, self.span));
        self.cx.ty_ptr(self.span, ty_u8, Mutability::Mut)