return lastModified;
    }

    protected static Analyzer getAnalyzer(final boolean ignoreCase) {
        return new Analyzer() {
            @Override
            protected TokenStreamComponents createComponents(final String fieldName) {
                final Tokenizer tokenizer = new KeywordTokenizer();
                final TokenStream stream = ignoreCase ? new LowerCaseFilter(tokenizer) : tokenizer;

        assertEquals(threadCount * objectsPerThread, createdComponents.size());

        // Check all components are unique (for prototype)
        for (int i = 0; i < createdComponents.size(); i++) {
            for (int j = i + 1; j < createdComponents.size(); j++) {
                assertNotSame(createdComponents.get(i), createdComponents.get(j));
            }
        }
    }

    /**