{"ast_node_type":"other","tokens":[{"end":48,"kind":"keyword","start":0,"text":"///"}]}
    /// a contract ensures clause, if it exists.
    /// Create an `ExprKind::Ret` that is optionally wrapped by a call to check
    fn checked_return(&mut self, opt_expr: Option<&'hir hir::Expr<'hir>>) -> hir::ExprKind<'hir> {