{"ast_node_type":"other","tokens":[{"end":48,"kind":"keyword","start":0,"text":"register(sym::contracts_requires,"}]}
    register(sym::contracts_requires, requires);
    let requires = SyntaxExtensionKind::Attr(Arc::new(contracts::ExpandRequires));
    let ensures = SyntaxExtensionKind::Attr(Arc::new(contracts::ExpandEnsures));