public static function css($files, $nest = true)
    {
        if (is_array($files)) {
            foreach ($files as $file) {
                self::cssCall($file, $nest);
            }
        } elseif (is_string($files)) {
            self::cssCall($files, $nest);
        }
    }
public static function css($files, $nest = true)
    {
        if (is_array($files)) {
            foreach ($files as $file) {
                self::cssCall($file, $nest);
            }
        } elseif (is_string($files)) {
            self::cssCall($files, $nest);
        }
    }
public static function css ( $ files , $ nest = true ) { if ( is_array ( $ files ) ) { foreach ( $ files as $ file ) { self :: cssCall ( $ file , $ nest ) ; } } elseif ( is_string ( $ files ) ) { self :: cssCall ( $ files , $ nest ) ; } }
Call CSS files.

@param string|array $files
@param bool         $nest

@return string
Call CSS files .