in client/src/main/scala/com.gu.contentapi.client/ContentApiClient.scala [151:153]
abstract override def get(url: String, headers: Map[String, String])(implicit context: ExecutionContext): Future[HttpResponse] = withRetry(backoffStrategy){ retryAttempt =>
super.get(url, headers + ("Request-Attempt" -> s"$retryAttempt"))
}