Lucene.Net.Util.LuceneTestCase.GetOnlySegmentReader C# (CSharp) Method

        public static SegmentReader GetOnlySegmentReader(DirectoryReader reader)
        {
            IList<AtomicReaderContext> subReaders = reader.Leaves;
            if (subReaders.Count != 1)
            {
                throw new System.ArgumentException(reader + " has " + subReaders.Count + " segments instead of exactly one");
            }
            AtomicReader r = (AtomicReader)subReaders[0].Reader;
            Assert.IsTrue(r is SegmentReader);
            return (SegmentReader)r;
        }