svoid testFullTextSearcher(SS texts, S query, IF1<S, Iterable<S>> searcher, TimeCollector tc) {
  Set<S> solution = asSet(keysWhereValue(s, s -> containingIC(query)));
  long time = nanos();
  Set<S> result = asCollection(searcher.get(query));
  tc.add(nanos()-time);
  for (S s : setDiff_bothWays(solution, result))
    fail("Searcher " + searcher + " was wrong on " + s);
}