public function removeSize($size)
    {
        $size = is_array($size) ? new Size($size[0], $size[1]) : $size;
        $key = "$size";

        if (isset($this->sizes[$key])) {
            unset($this->sizes[$key]);
        }

        if (isset($this->sizeUrls[$key])) {
            unset($this->sizeUrls[$key]);
        }

        return $this;
    }