Lucene.Net.Search.PrefixQuery.GetTermsEnum C# (CSharp) Method

        public override TermsEnum GetTermsEnum(Terms terms, AttributeSource atts)
        {
            TermsEnum tenum = terms.Iterator(null);

            if (Prefix_Renamed.Bytes().Length == 0)
            {
                // no prefix -- match all terms for this field:
                return tenum;
            }
            return new PrefixTermsEnum(tenum, Prefix_Renamed.Bytes());
        }

        public virtual void TestPrefixQuery_Mem()
        {
            Directory directory = NewDirectory();

            string[] categories = new string[] { "/Computers", "/Computers/Mac", "/Computers/Windows" };
            RandomIndexWriter writer = new RandomIndexWriter(Random(), directory, Similarity, TimeZone);
            for (int i = 0; i < categories.Length; i++)
            {
                Document doc = new Document();
                doc.Add(NewStringField("category", categories[i], Field.Store.YES));
                writer.AddDocument(doc);
            }
            IndexReader reader = writer.Reader;

            PrefixQuery query = new PrefixQuery(new Term("category", "/Computers"));
            IndexSearcher searcher = NewSearcher(reader);
            ScoreDoc[] hits = searcher.Search(query, null, 1000).ScoreDocs;
            Assert.AreEqual(3, hits.Length, "All documents in /Computers category and below");

            query = new PrefixQuery(new Term("category", "/Computers/Mac"));
            hits = searcher.Search(query, null, 1000).ScoreDocs;
            Assert.AreEqual(1, hits.Length, "One in /Computers/Mac");

            query = new PrefixQuery(new Term("category", ""));
            Terms terms = MultiFields.GetTerms(searcher.IndexReader, "category");
            Assert.IsFalse(query.GetTermsEnum(terms) is PrefixTermsEnum);
            hits = searcher.Search(query, null, 1000).ScoreDocs;
            Assert.AreEqual(3, hits.Length, "everything");
            writer.Dispose();
            reader.Dispose();
            directory.Dispose();
        }