public function signRequestHeaders(
		$httpVerb = 'GET',
		$path = '/',
		$query = array(),
		$headers = null,
		$forTableStorage = false,
		$resourceType = Storage::RESOURCE_UNKNOWN,
		$requiredPermission = CredentialsAbstract::PERMISSION_READ,
		$rawData = null
	) {
	    return $headers;
	}