public virtual void TestNullDocIdSet()
{
Directory dir = NewDirectory();
RandomIndexWriter writer = new RandomIndexWriter(Random(), dir, Similarity, TimeZone);
writer.Dispose();
IndexReader reader = SlowCompositeReaderWrapper.Wrap(DirectoryReader.Open(dir));
AtomicReaderContext context = (AtomicReaderContext)reader.Context;
Filter filter = new FilterAnonymousInnerClassHelper(this, context);
CachingWrapperFilter cacher = new CachingWrapperFilter(filter);
// the caching filter should return the empty set constant
//Assert.IsNull(cacher.GetDocIdSet(context, "second time", (context.AtomicReader).LiveDocs));
Assert.IsNull(cacher.GetDocIdSet(context, (context.AtomicReader).LiveDocs));
reader.Dispose();
dir.Dispose();
}