{"ast_node_type":"other","tokens":[{"end":42,"kind":"keyword","start":0,"text":"///"}]}
        /// corresponding to the ellipsis.
        /// If `pat` is a `...` pattern, return the start and end of the range, as well as the span
        fn matches_ellipsis_pat(pat: &ast::Pat) -> Option<(Option<&Expr>, &Expr, Span)> {