public function renderCss()
	{
		$result = "";
		$css = $this->getCss();
		if(!empty($css))
		array_walk($css, function($value) use (&$result){
			$result .= '<link href="'.$value.'" type="text/css" rel="stylesheet">';
		});
		$custom = $this->getCustomCss();
		if(!empty($custom))
		{
			$customCss = '<style type="text/css" rel="stylesheet" id="silex-assets-service-css-'.substr(md5(time()),0,5).'">';
			if($custom !== array())
				array_walk($custom, function($value) use (&$customCss){
					$customCss .= $value."\n";
				});
			$customCss .= "</style>";
			$result .= $customCss;
		}
		return $result;
	}