MDC { public static void clear() { ThreadContext.clear(); } private  MDC(); @SuppressWarnings({ "rawtypes", "unchecked" }) static Hashtable getContext(); static Object get(final String key); static void put(final String key, final Object value); static void remove(final String key); static void clear();  }
@Test public void clearValues() { MDC.clear(); verify(provider).clear(); }