/// <summary> Uses the {@link FilterManager} to keep the cache for a filter on the
/// searcher side of a remote connection.
/// </summary>
/// <param name="reader">the index reader for the Filter
/// </param>
/// <returns> the DocIdSet
/// </returns>
public override DocIdSet GetDocIdSet(IndexReader reader)
{
Filter cachedFilter = FilterManager.GetInstance().GetFilter(filter);
return(cachedFilter.GetDocIdSet(reader));
}