@SuppressWarnings("unchecked")
  public static Set<File> getActiveLogFiles() throws IOException {
    Method method = getMethod("getActiveLogFiles");
    try {
      return (Set<File>) method.invoke(null);
    } catch (IllegalAccessException e) {
      throw new AssertionError("should not happen", e);
    } catch (InvocationTargetException e) {
      Throwable cause = e.getCause();
      throwUnchecked(cause);
      if (cause instanceof IOException) {
        throw (IOException) cause;
      }
      throw new AssertionError("should not happen", cause);
    }
  }
A bridge class for operating on log4j, such as changing log level, etc.
<p/>
Will call the methods in {@link InternalLog4jUtils} to actually operate on the log4j stuff.
hbase-logging/src/main/java/org/apache/hadoop/hbase/logging/Log4jUtils.java