{"ast_node_type":"function","tokens":[{"end":86,"kind":"keyword","start":0,"text":"fn"}]}
    fn from_line(&self, line: &str, error: &mut String) -> Option<CargoCheckMessage> {
impl CargoParser<CargoCheckMessage> for CargoCheckParser {
        let mut deserializer = serde_json::Deserializer::from_str(line);