code: public void removeNamingObjectListener(NamingObjectListener nol) {
          if (nol == null)
              throw new IllegalArgumentException("The NameingObjectListener must not be null");
  
          ArrayList listener = getListener();
          synchronized(listener) {
              if (!listener.contains(nol))
                  return;
              listener.remove(nol);
          }
      }
docs: This method will remove a <code>NamingObjectListener</code> from the set of listeners.  If the
  It is safe to call this if the NamingObjectListener hasn't been added to the listener list.
  @param nol The <code>NamingObjectListener</code> to remove as a listener.  This must not be null.
  @throws IllegalArgumentException when nol is null.