final protected function loadChoicesFromQuery(string $query, string $columnName, string $connectionName = null)
    {
        $connection = $connectionName
            ? $this->connectionRegistry->getHttpConnection($connectionName)
            : $this->connectionRegistry->getDefaultHttpConnection()
        ;
        $measurements = array_map(function ($point) use ($columnName) {
            return $point[$columnName];
        }, $connection->query($query)->getPoints());

        return array_combine(array_values($measurements), $measurements);
    }