static L<WithURL<S>> youTubeSearch_all(Browser browser, S query, double cacheExpirationDays default 1) {
  // simplify query
  query = simpleSpacesAndTrim(lower(query));
  
  FileBasedStringMap cache = new(javaxCachesDir("YouTube Searches"));
  File f = cache.fileForKey(query);
  if (exists(f) && fileAgeInDays(f) < cacheExpirationDays)
    ret (L) unstructure(cache.get(query));
  
  // not in cache, start browser
  
  var result = youTubeSearch_uncached(browser, query);
  cache.put(query, indentedStructure(result));
  ret result;
}