{"ast_node_type":"variable","tokens":[{"end":34,"kind":"keyword","start":0,"text":"let"}]}
        let fsc = builder.build();
        builder.add_file_set(vec![VfsPath::new_virtual_path("/ROOT/def/ghi/jkl".to_owned())]);
        let src = SourceRootConfig { fsc, local_filesets: vec![0, 1, 2] };