{"ast_node_type":"other","tokens":[{"end":88,"kind":"keyword","start":0,"text":"self.psess.gated_spans.gate(sym::contracts_internals,"}]}
            self.psess.gated_spans.gate(sym::contracts_internals, self.prev_token.span);
        let ensures = if self.eat_keyword_noexpect(exp!(ContractEnsures).kw) {
            let postcond = self.parse_expr()?;