private static void clearAntStaticCache(final Class<?> helperClass) {
    // for ant 1.7, there is a dedicated method for cache clearing
    try {
      helperClass.getDeclaredMethod("clearCache").invoke(null);
    }
    catch (Throwable e) {
      try {
        // assume it is older version of ant
        Map helpersCollection = ReflectionUtil.getField(helperClass, null, null, "helpers");
        if (helpersCollection != null) {
          helpersCollection.clear();
        }
      }
      catch (Throwable _e) {
        // ignore.
      }
    }
  }
private static void clearAntStaticCache(final Class<?> helperClass)