code: private void baseInstanceModified() {
          ContextServiceImpl[] listeners;
  
          lock.writeLock().lock();
          try {
              listeners = modificationListeners.toArray(new ContextServiceImpl[modificationListeners.size()]);
              modificationListeners.clear();
              threadContextConfigurations = null;
          } finally {
              lock.writeLock().unlock();
          }
  
          for (ContextServiceImpl listener : listeners)
              listener.baseInstanceModified();
      }
docs: This notification is sent by the base instance (if any) when it is modified
  so that we can uninitialize, so that the next time we are used we can honor
  the updates to the base instance.