withLabel("topology.kubernetes.io/region", "region-a").
					withLabel("topology.kubernetes.io/zone", "zone-a").Node,
				makeNode("zone-a-node-b").
					withLabel("topology.kubernetes.io/region", "region-a").
					withLabel("topology.kubernetes.io/zone", "zone-a").Node,
				makeNode("zone-b-node-a").
					withLabel("topology.kubernetes.io/region", "region-b").
					withLabel("topology.kubernetes.io/zone", "zone-b").Node,

	"strings"
)

// ARN - SQS resource name representation.
type ARN struct {
	TargetID
	region string
}

// String - returns string representation.
func (arn ARN) String() string {
	if arn.TargetID.ID == "" && arn.TargetID.Name == "" && arn.region == "" {
		return ""
	}

	return "arn:minio:s3-object-lambda:" + arn.region + ":" + arn.TargetID.String()
}

// ParseARN - parses string to ARN.

// failure.
template <typename OpT>
LogicalResult GetOp(Region* region, OpT* result) {
  *result = {};
  for (auto op : region->getOps<OpT>()) {
    if (*result) return op.emitError("should be unique within a function");
    *result = op;
  }
  return success();
}

LogicalResult RunOnRegion(Region* region) {
  RecvTPUEmbeddingActivationsOp recv_op;
  if (failed(GetOp(region, &recv_op))) return failure();

  void runOnOperation() override;
};

// Collects all reachable functions (via call ops) from a given region.
SmallVector<func::FuncOp, 4> CollectReachableFunctions(Region& region) {
  llvm::SmallPtrSet<func::FuncOp, 4> reachable_funcs;

  auto collect_reachable_funcs =
      [&reachable_funcs](Region& src,
                         SmallVectorImpl<func::FuncOp>& funcs_to_visit) {

	RegionSize uintptr
	// The state of the pages in the region.
	State uint32
	// The access protection of the pages in the region.
	Protect uint32
	// The type of pages in the region.
	Type uint32

  auto walk_result = parent_op->walk([](Operation *op) {
    // Cleanup code in attached regions.
    for (Region &region : op->getRegions()) {
      if (!llvm::hasSingleElement(region)) return WalkResult::interrupt();
      RemovePassthroughOp(region.front());
      RemoveDeadLocalVariables(region.front());
    }

    LogicalResult result = success();

	}
	return newAPIEndpoints
}

// Prints common server startup message. Prints credential, region and browser access.
func printServerCommonMsg(apiEndpoints []string) {
	// Get saved credentials.
	cred := globalActiveCred

	// Get saved region.
	region := globalSite.Region()

	apiEndpointStr := strings.TrimSpace(strings.Join(apiEndpoints, "  "))
	// Colorize the message and print.

// returns ErrNone if the signature matches.
func doesPolicySignatureV4Match(formValues http.Header) (auth.Credentials, APIErrorCode) {
	// Server region.
	region := globalSite.Region()

	// Parse credential tag.
	credHeader, s3Err := parseCredentialHeader("Credential="+formValues.Get(xhttp.AmzCredential), region, serviceS3)
	if s3Err != ErrNone {
		return auth.Credentials{}, s3Err
	}

	r := &http.Request{Header: formValues}

  // Regions that contains ops requiring token input attributes.
  absl::flat_hash_set<Region*> regions_with_token;
  while (!worklist.empty()) {
    Operation* op = worklist.back();
    worklist.pop_back();

    Region* region = op->getParentRegion();
    regions_with_token.insert(region);

    // If the parent is not a FuncOp, then add the parent op containing a region
    // to worklist.

		want string
	}{
		{
			arn: ARN{
				Partition:    "minio",
				Service:      "iam",
				Region:       "us-east-1",
				ResourceType: "role",
				ResourceID:   "my-role",
			},
			want: "arn:minio:iam:us-east-1::role/my-role",
		},
		{
			arn: ARN{
				Partition:    "minio",
				Service:      "",
				Region:       "us-east-1",
				ResourceType: "role",
				ResourceID:   "my-role",
			},