{"ast_node_type":"variable","tokens":[{"end":55,"kind":"keyword","start":0,"text":"let"}]}
    let path_mapping = config.opts.file_path_mapping();
    let file_loader = config.file_loader.unwrap_or_else(|| Box::new(RealFileLoader));
    let hash_kind = config.opts.unstable_opts.src_hash_algorithm(&target);