{"ast_node_type":"function","tokens":[{"end":97,"kind":"keyword","start":0,"text":"pub"}]}
    pub fn param_at(&'tcx self, param_index: usize, tcx: TyCtxt<'tcx>) -> &'tcx GenericParamDef {
    /// Returns the `GenericParamDef` with the given index.
        if let Some(index) = param_index.checked_sub(self.parent_count) {