{"ast_node_type":"variable","tokens":[{"end":84,"kind":"keyword","start":0,"text":"let"}]}
        let rustc_source = self.rustc_source(source_root).as_ref().map(|rustc_src| {
    pub fn cargo(&self, source_root: Option<SourceRootId>) -> CargoConfig {
            if rustc_src == "discover" {