{"ast_node_type":"other","tokens":[{"end":75,"kind":"keyword","start":0,"text":"//"}]}
    // we could look up the `ExpnData` from the metadata of foreign crates,
    // `ExpnData` (e.g `ExpnData.krate` may not be `LOCAL_CRATE`). Alternatively,
    // but it seemed easier to have `OnDiskCache` be independent of the `CStore`.