{"ast_node_type":"other","tokens":[{"end":44,"kind":"keyword","start":0,"text":"self.look_ahead(1,"}]}
        self.look_ahead(1, |t| t.is_ident())
        // `{ ident, ` and `{ ident: ` cannot start a block.
            && self.look_ahead(2, |t| t == &token::Comma || t == &token::Colon)