### Question:
ConcatFilterFactory implements TokenFilterFactory { public TokenFilter createTokenFilter(TokenStream tokenStream, Properties properties) throws IOException { String concatString = properties.getProperty(CONCAT_STRING_PARAMETER); return new ConcatFilter(tokenStream, concatString); }  TokenFilter createTokenFilter(TokenStream tokenStream,
			Properties properties); void preloadResources(Properties properties); static final String CONCAT_STRING_PARAMETER; }### Answer:
@Test public void testCreateTokenFilter() throws IOException{ Properties properties = new Properties(); properties.setProperty(ConcatFilterFactory.CONCAT_STRING_PARAMETER, "|"); ConcatFilter concatFilter = (ConcatFilter) concatFilterFactory.createTokenFilter(tokenStream, properties ); assertNotNull(concatFilter); assertEquals("|", concatFilter.getConcatString()); }