boolean autoCommit = (0==pass);
MockRAMDirectory dir = new MockRAMDirectory();
IndexWriter modifier = new IndexWriter(dir, autoCommit,
new WhitespaceAnalyzer(), true);
dir.failOn(failure.reset());
for (int i = 0; i < keywords.length; i++) {
Document doc = new Document();
doc.add(new Field("id", keywords[i], Field.Store.YES,
Field.Index.UN_TOKENIZED));