protected function formatKeys($keys)
	{
		if (! is_array($keys))
		{
			return $keys;
		}

		$return = [];

		foreach ($keys as $name => $key)
		{
			$return[$name] = [
				'fields' => $key->fields,
				'type'   => 'index',
			];
		}

		return $return;
	}