private static function checkProvidedUri($uri)
    {
        $returnValue = (string) '';

        
        if($uri != '') {
        	if(common_Utils::isUri($uri)){
        		$returnValue = $uri;
        	}
        	else{
        		throw new common_Exception("Could not create new Resource, malformed URI provided: '" . $uri . "'.");
        	}
        }
        else{
        	$returnValue = common_Utils::getNewUri();
        }
        

        return (string) $returnValue;
    }