* with one that returns null for getSequentialSubReaders.
*/
public static IndexSearcher newSearcher(IndexReader r, boolean maybeWrap) throws IOException {
if (random.nextBoolean()) {
if (maybeWrap && rarely()) {
r = new SlowMultiReaderWrapper(r);
}
return new AssertingIndexSearcher(r);
} else {
int threads = 0;
final ExecutorService ex = (random.nextBoolean()) ? null