PHP OOP รับ array แล้วใช้ foreach แต่ออกเฉพาะค่าสุดท้าย

$css_files = array('css/bootstrap/bootstrap.min.css', 
	'css/bootstrap/bootstrap-responsive.min.css', 
	'css/supr-theme/jquery.ui.supr.css',
	'css/icons.css',
	'plugins/misc/qtip/jquery.qtip.css',
	'plugins/misc/fullcalendar/fullcalendar.css',
	'plugins/misc/search/tipuesearch.css',
	'plugins/forms/uniform/uniform.default.css',
	'css/main.css',
	'css/custom.css');

$LoadHTML = new lHTMLh();
$LoadHTML->SetCSS($css_files);
echo $LoadHTML->CSS;

class lHTMLh
{
    Public $CSS;

    Public function SetCSS($s1)
    {
        foreach ($s1 as $key => $value) {
          $this->CSS = "<link rel='stylesheet' type='text/css' media='screen,projection' href=$value />";
        }
        return $this->CSS;
    }

}

foreach ($css_files as $key => $value) {
	echo $value."<br>";

}