Text_Diff::countDeletedLines

    function countDeletedLines()
    {
        $count = 0;
        foreach ($this->_edits as $edit) {
            if (is_a($edit, 'Text_Diff_Op_delete') ||
                is_a($edit, 'Text_Diff_Op_change')) {
                $count += $edit->norig();
            }
        }
        return $count;
    }