public function setBorders(PHPRtfLite_Border_Format $borderFormat,
                               $left = true, $top = true, $right = true, $bottom = true)
    {
        $borderFormat->setColorTable($this->_rtf->getColorTable());

        if ($left) {
            $this->_borderLeft  = $borderFormat;
        }

        if ($top) {
            $this->_borderTop   = $borderFormat;
        }

        if ($right) {
            $this->_borderRight = $borderFormat;
        }

        if ($bottom) {
            $this->_borderBottom = $borderFormat;
        }
    }