private void runFormatterTests(Bundle bundle, Collection<Class<?>> testClasses, String fileNameExtension) {
String collectionName = bundle.getSymbolicName() + AUTO_TEST_SUITE_SUFFIX;
List<JUnit4Formatter> formatters = new ArrayList<JUnit4Formatter>();
File file = new File( resultsDirectory, bundle.getSymbolicName() + fileNameExtension + TEST_RESULT_EXTENSION );
formatters.add( new XmlJUnit4Formatter( file ) );
JUnit4TestRunner testRunner = new JUnit4TestRunner();
boolean success = testRunner.runFormatterTests( collectionName, testClasses, formatters ).wasSuccessful();
mergeTestResult( success ? AutoTestRunner.SUCCESS : AutoTestRunner.FAILURES );
}