public IndexSearcher acquire(long version) {ensureOpen();final SearcherTracker tracker = searchers.get(version);if (tracker != null &&tracker.searcher.getIndexReader().tryIncRef()) {return tracker.searcher;}return null;}

public virtual IndexSearcher Acquire(long version){EnsureOpen();Lazy<SearcherTracker> tracker;if (_searchers.TryGetValue(version, out tracker) && tracker.IsValueCreated && tracker.Value.Searcher.IndexReader.TryIncRef()){return tracker.Value.Searcher;}return null;}
