code: public Map<String,Object> handleUpdateFilterMap(Map<String,Object> propFilter)
      {
          if (propFilter != null)
          {
              Object bookmark = propFilter.get(ADD_BOOKMARK);
              if (bookmark != null)
              {
                  if (CLEAR_BOOKMARKS.equals(bookmark))
                  {
                  	if (m_htBookmarks != null)
                  		m_htBookmarks.clear();
                      m_strSecondaryKey = null;             // The secondary key to watch for.
                      m_objKeyData = null;                  // The reference value to watch for.
                      String strHint = (String)propFilter.get(SECOND_KEY_HINT);
                      if (strHint != null)
                      {
                          Object objKeyData = propFilter.get(strHint);    // The value of the 2nd key reference data.
                          m_strSecondaryKey = strHint;                    // The secondary key to watch for.
                          m_objKeyData = objKeyData;                      // The reference value to watch for.
                      }
                  }
                  else
                  {
                  	if (m_htBookmarks != null)
                  		if (!m_htBookmarks.contains(bookmark))
                  			m_htBookmarks.add(bookmark);
                  }
              }
          }
          return super.handleUpdateFilterMap(propFilter);   // Update any remote copy of this.
      }
docs: Update this filter with this new information.
  Override this to do something locally.
  Remember to call super after updating this filter, as this method updates the remote copy of this filter.
  @param properties New filter information (ie, bookmark=345).
  @return The new filter change map (must contain enough information for the remote filter to sync).