public function addStyle($href, $path = null)
    {
        $key = $this->calculateKey($href, $path);
        $this->styles[$key] = 1;

        return $this;
    }
public function addStyle($href, $path = null)
    {
        $key = $this->calculateKey($href, $path);
        $this->styles[$key] = 1;

        return $this;
    }
public function addStyle ( $ href , $ path = null ) { $ key = $ this -> calculateKey ( $ href , $ path ) ; $ this -> styles [ $ key ] = 1 ; return $ this ; }
this method add css file

@param string $href
@param string $path
@return Style
this method add css file