{"ast_node_type":"variable","tokens":[{"end":66,"kind":"keyword","start":0,"text":"let"}]}
        let &(_, i) = self.names.iter().find(|(n, _)| n == name)?;
    pub fn by_name(&self, name: &Name) -> Option<(usize, &FormatArgument)> {
        Some((i, &self.arguments[i]))