private CompletableFuture<DescribeContainerInstancesResponse> describeContainerInstances(
      List<String> arns) {
    return ecs.describeContainerInstances(describeRequest.copy().containerInstances(arns).build());
  }
Wrapper around paginated ECS list/describe ContainerInstance APIs that efficiently describes all
tasks.
scheduling-manager/src/main/java/com/amazonaws/blox/scheduling/state/ContainerInstanceLister.java