public function appendAttributes(array $attrs, $options = ["option" => "append"]) {
        $url = "entities/{$this->_id}/attrs";

        if ($this->_type) {
            $url .= "?type={$this->_type}";
        }

        if (count($options) > 0) {
            $prefix = ($this->_type) ? "&" : "?";
            $url .= $prefix . urldecode(http_build_query($options));
        }

        $updateEntity = new ContextFactory($attrs);
        return $this->_orion->create($url, $updateEntity);
    }