_end_block example

      elseif ($edit->type == 'delete') {
        $this->_deleted($edit->orig);
      }
      elseif ($edit->type == 'change') {
        $this->_changed($edit->orig, $edit->closing);
      }
      else {
        trigger_error('Unknown edit type', E_USER_ERROR);
      }
    }
    $this->_end_block();
  }

  protected function _start_diff() {
    ob_start();
  }

  protected function _end_diff() {
    $val = ob_get_contents();
    ob_end_clean();
    return $val;
  }