private function getGranularity()
    {
        // If the granularity is not specified, attempt to retrieve it from the server
        // Fall back on DATE granularity
        if ($this->granularity === null) {
            $response = $this->identify();
            return (isset($response->Identify->granularity))
                ? (string) $response->Identify->granularity
                : Granularity::DATE;
        }

        return $this->granularity;
    }