if (value.getClass() == DownloadSourceDO.class) {
if (value == null){ return null; } else if (value.getClass() == DownloadSourceDO.class) {
    public String getToolTipText(MouseEvent me){        if (!Settings.getSettings().isToolTipEnabled()) {            return null;        }        Point p = me.getPoint();        int column = columnAtPoint(p);        if (column == 0){            int row = rowAtPoint(p);            Object value = ( (TreeTableModelAdapter) getModel()).                nodeForRow(row);            if (value.getClass() == DownloadSourceDO.class) {                return getToolTipForDownloadSourceDO( (DownloadSourceDO) value);            }            else if (value.getClass() == DownloadMainNode.class                &&                ( (DownloadMainNode) value).getType() ==                DownloadMainNode.ROOT_NODE) {                return getToolTipForDownloadDO(( (DownloadMainNode) value).getDownloadDO());            }            else{                return null;            }        }        else{            return null;        }    }