docs: public void removeDuplicateFilters(JMessageListener listenerToCheck)
      {
          for (int iIndex = 0; ; iIndex++)
          {
              BaseMessageFilter filter = listenerToCheck.getListenerMessageFilter(iIndex);
              if (filter == null)
                  break;
              if (this.isSameFilter(filter))
              {
                  if (filter.getMessageListener(1) == null)
                  {   // Only free if the message list is the same and only
                      filter.removeFilterMessageListener(listenerToCheck);
                  // DO NOT free the listener.
                      filter.free();     // Cool, it was a dup... get rid of it.
                      iIndex--;
                  }
              }
          }
      }