// returns an ID for each test result
 private int getTestId(ITestResult result) {
   int id = result.getTestClass().getName().hashCode();
   id = 31 * id + result.getMethod().getMethodName().hashCode();
   id = 31 * id + (result.getParameters() != null ? Arrays.hashCode(result.getParameters()) : 0);
   return id;
 }