go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.43.0: New

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify New in pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp@v1.43.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp@v1.43.0
Demonstrate these symbols/APIs:
  - New

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:bd3ea544990c5e796ce8866b98239e9d03d6a4360951fde1baa032c7403536c0","contract":["otlpmetrichttp.New creates a non-nil Exporter with default configuration that flushes and shuts down cleanly","otlpmetrichttp.New configures custom headers, HTTP client, and exports metric records via HTTP POST with application/x-protobuf","otlpmetrichttp.New with WithCompression(otlpmetrichttp.GzipCompression) transmits payloads with Content-Encoding gzip","otlpmetrichttp.New exporter returns an error when the export endpoint returns a non-2xx status code"],"goal":"verify New in pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp@v1.43.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp@v1.43.0"],"schemaVersion":1,"symbols":["New"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp@v1.43.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp@v1.43.0","symbols":["New"],"verifierAdapter":"golang@1"}

module example.com/otlpmetrichttp-sample

go 1.26.6

require (
	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.43.0
	go.opentelemetry.io/otel/sdk/metric v1.43.0
)

require (
	github.com/cenkalti/backoff/v5 v5.0.3 // indirect
	github.com/cespare/xxhash/v2 v2.3.0 // indirect
	github.com/go-logr/logr v1.4.3 // indirect
	github.com/go-logr/stdr v1.2.2 // indirect
	github.com/google/uuid v1.6.0 // indirect
	github.com/grpc-ecosystem/grpc-gateway/v2 v2.28.0 // indirect
	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
	go.opentelemetry.io/otel v1.43.0 // indirect
	go.opentelemetry.io/otel/metric v1.43.0 // indirect
	go.opentelemetry.io/otel/sdk v1.43.0 // indirect
	go.opentelemetry.io/otel/trace v1.43.0 // indirect
	go.opentelemetry.io/proto/otlp v1.10.0 // indirect
	golang.org/x/net v0.52.0 // indirect
	golang.org/x/sys v0.42.0 // indirect
	golang.org/x/text v0.35.0 // indirect
	google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9 // indirect
	google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 // indirect
	google.golang.org/grpc v1.80.0 // indirect
	google.golang.org/protobuf v1.36.11 // indirect
)

github.com/cenkalti/backoff/v5 v5.0.3 h1:ZN+IMa753KfX5hd8vVaMixjnqRZ3y8CuJKRKj1xcsSM=
github.com/cenkalti/backoff/v5 v5.0.3/go.mod h1:rkhZdG3JZukswDf7f0cwqPNk4K0sa+F97BxZthm/crw=
github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
github.com/grpc-ecosystem/grpc-gateway/v2 v2.28.0 h1:HWRh5R2+9EifMyIHV7ZV+MIZqgz+PMpZ14Jynv3O2Zs=
github.com/grpc-ecosystem/grpc-gateway/v2 v2.28.0/go.mod h1:JfhWUomR1baixubs02l85lZYYOm7LV6om4ceouMv45c=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
go.opentelemetry.io/otel v1.43.0 h1:mYIM03dnh5zfN7HautFE4ieIig9amkNANT+xcVxAj9I=
go.opentelemetry.io/otel v1.43.0/go.mod h1:JuG+u74mvjvcm8vj8pI5XiHy1zDeoCS2LB1spIq7Ay0=
go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.43.0 h1:w1K+pCJoPpQifuVpsKamUdn9U0zM3xUziVOqsGksUrY=
go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp v1.43.0/go.mod h1:HBy4BjzgVE8139ieRI75oXm3EcDN+6GhD88JT1Kjvxg=
go.opentelemetry.io/otel/metric v1.43.0 h1:d7638QeInOnuwOONPp4JAOGfbCEpYb+K6DVWvdxGzgM=
go.opentelemetry.io/otel/metric v1.43.0/go.mod h1:RDnPtIxvqlgO8GRW18W6Z/4P462ldprJtfxHxyKd2PY=
go.opentelemetry.io/otel/sdk v1.43.0 h1:pi5mE86i5rTeLXqoF/hhiBtUNcrAGHLKQdhg4h4V9Dg=
go.opentelemetry.io/otel/sdk v1.43.0/go.mod h1:P+IkVU3iWukmiit/Yf9AWvpyRDlUeBaRg6Y+C58QHzg=
go.opentelemetry.io/otel/sdk/metric v1.43.0 h1:S88dyqXjJkuBNLeMcVPRFXpRw2fuwdvfCGLEo89fDkw=
go.opentelemetry.io/otel/sdk/metric v1.43.0/go.mod h1:C/RJtwSEJ5hzTiUz5pXF1kILHStzb9zFlIEe85bhj6A=
go.opentelemetry.io/otel/trace v1.43.0 h1:BkNrHpup+4k4w+ZZ86CZoHHEkohws8AY+WTX09nk+3A=
go.opentelemetry.io/otel/trace v1.43.0/go.mod h1:/QJhyVBUUswCphDVxq+8mld+AvhXZLhe+8WVFxiFff0=
go.opentelemetry.io/proto/otlp v1.10.0 h1:IQRWgT5srOCYfiWnpqUYz9CVmbO8bFmKcwYxpuCSL2g=
go.opentelemetry.io/proto/otlp v1.10.0/go.mod h1:/CV4QoCR/S9yaPj8utp3lvQPoqMtxXdzn7ozvvozVqk=
golang.org/x/net v0.52.0 h1:He/TN1l0e4mmR3QqHMT2Xab3Aj3L9qjbhRm78/6jrW0=
golang.org/x/net v0.52.0/go.mod h1:R1MAz7uMZxVMualyPXb+VaqGSa3LIaUqk0eEt3w36Sw=
golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
gonum.org/v1/gonum v0.17.0 h1:VbpOemQlsSMrYmn7T2OUvQ4dqxQXU+ouZFQsZOx50z4=
gonum.org/v1/gonum v0.17.0/go.mod h1:El3tOrEuMpv2UdMrbNlKEh9vd86bmQ6vqIcDwxEOc1E=
google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9 h1:VPWxll4HlMw1Vs/qXtN7BvhZqsS9cdAittCNvVENElA=
google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9/go.mod h1:7QBABkRtR8z+TEnmXTqIqwJLlzrZKVfAUm7tY3yGv0M=
google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 h1:m8qni9SQFH0tJc1X0vmnpw/0t+AImlSvp30sEupozUg=
google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
google.golang.org/grpc v1.80.0 h1:Xr6m2WmWZLETvUNvIUmeD5OAagMw3FiKmMlTdViWsHM=
google.golang.org/grpc v1.80.0/go.mod h1:ho/dLnxwi3EDJA4Zghp7k2Ec1+c2jqup0bFkw07bwF4=
google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package otlpmetrichttpsample

import (
	"context"
	"net/http"

	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp"
)

// NewExporter creates a new OTLP HTTP metric exporter with the provided options.
func NewExporter(ctx context.Context, opts ...otlpmetrichttp.Option) (*otlpmetrichttp.Exporter, error) {
	return otlpmetrichttp.New(ctx, opts...)
}

// NewExporterWithHTTPClient creates a new OTLP HTTP metric exporter with a custom HTTP client and endpoint.
func NewExporterWithHTTPClient(ctx context.Context, client *http.Client, endpointURL string, opts ...otlpmetrichttp.Option) (*otlpmetrichttp.Exporter, error) {
	allOpts := append([]otlpmetrichttp.Option{
		otlpmetrichttp.WithHTTPClient(client),
		otlpmetrichttp.WithEndpointURL(endpointURL),
		otlpmetrichttp.WithInsecure(),
	}, opts...)
	return otlpmetrichttp.New(ctx, allOpts...)
}

{
  "schemaVersion": 1,
  "goal": "verify New in pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp@v1.43.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp@v1.43.0"
  ],
  "symbols": [
    "New"
  ]
}

package main

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"os"
	"strings"
	"sync"
	"time"

	otlpmetrichttpsample "example.com/otlpmetrichttp-sample"
	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp"
	"go.opentelemetry.io/otel/sdk/metric"
	"go.opentelemetry.io/otel/sdk/metric/metricdata"
)

func main() {
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()

	// 1. Assertion: otlpmetrichttp.New creates a non-nil Exporter with default configuration that flushes and shuts down cleanly
	defaultExp, err := otlpmetrichttpsample.NewExporter(
		ctx,
		otlpmetrichttp.WithEndpointURL("http://127.0.0.1:4318/v1/metrics"),
		otlpmetrichttp.WithInsecure(),
		otlpmetrichttp.WithRetry(otlpmetrichttp.RetryConfig{Enabled: false}),
	)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: NewExporter failed: %v\n", err)
		os.Exit(1)
	}
	if defaultExp == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected non-nil default exporter\n")
		os.Exit(1)
	}
	if err := defaultExp.ForceFlush(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: defaultExp.ForceFlush failed: %v\n", err)
		os.Exit(1)
	}
	if err := defaultExp.Shutdown(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: defaultExp.Shutdown failed: %v\n", err)
		os.Exit(1)
	}

	// 2. Assertion: otlpmetrichttp.New configures custom headers, HTTP client, and exports metric records via HTTP POST with application/x-protobuf
	var (
		mu          sync.Mutex
		receivedReq *http.Request
		reqBody     []byte
	)

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		mu.Lock()
		defer mu.Unlock()
		receivedReq = r
		body, _ := io.ReadAll(r.Body)
		reqBody = body
		w.Header().Set("Content-Type", "application/x-protobuf")
		w.WriteHeader(http.StatusOK)
	}))
	defer server.Close()

	customHeaders := map[string]string{
		"X-Sample-Tenant": "tenant-42",
		"X-Custom-Env":    "production",
	}

	exp, err := otlpmetrichttpsample.NewExporterWithHTTPClient(
		ctx,
		server.Client(),
		server.URL+"/v1/metrics",
		otlpmetrichttp.WithHeaders(customHeaders),
		otlpmetrichttp.WithTimeout(3*time.Second),
		otlpmetrichttp.WithCompression(otlpmetrichttp.NoCompression),
		otlpmetrichttp.WithRetry(otlpmetrichttp.RetryConfig{Enabled: false}),
	)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: NewExporterWithHTTPClient failed: %v\n", err)
		os.Exit(1)
	}

	reader := metric.NewPeriodicReader(exp)
	provider := metric.NewMeterProvider(metric.WithReader(reader))
	meter := provider.Meter("sample-meter")
	counter, err := meter.Int64Counter("sample_counter")
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: Int64Counter failed: %v\n", err)
		os.Exit(1)
	}
	counter.Add(ctx, 42)

	if err := provider.ForceFlush(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: provider.ForceFlush failed: %v\n", err)
		os.Exit(1)
	}

	mu.Lock()
	if receivedReq == nil {
		mu.Unlock()
		fmt.Fprintf(os.Stderr, "FAIL: mock server received no request\n")
		os.Exit(1)
	}

	if receivedReq.Method != http.MethodPost {
		fmt.Fprintf(os.Stderr, "FAIL: expected HTTP POST, got %s\n", receivedReq.Method)
		mu.Unlock()
		os.Exit(1)
	}

	if !strings.HasPrefix(receivedReq.Header.Get("Content-Type"), "application/x-protobuf") {
		fmt.Fprintf(os.Stderr, "FAIL: expected application/x-protobuf Content-Type, got %s\n", receivedReq.Header.Get("Content-Type"))
		mu.Unlock()
		os.Exit(1)
	}

	if got := receivedReq.Header.Get("X-Sample-Tenant"); got != "tenant-42" {
		fmt.Fprintf(os.Stderr, "FAIL: expected X-Sample-Tenant header 'tenant-42', got %q\n", got)
		mu.Unlock()
		os.Exit(1)
	}

	if got := receivedReq.Header.Get("X-Custom-Env"); got != "production" {
		fmt.Fprintf(os.Stderr, "FAIL: expected X-Custom-Env header 'production', got %q\n", got)
		mu.Unlock()
		os.Exit(1)
	}

	if len(reqBody) == 0 {
		fmt.Fprintf(os.Stderr, "FAIL: expected non-empty request body\n")
		mu.Unlock()
		os.Exit(1)
	}
	mu.Unlock()

	if err := provider.Shutdown(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: provider.Shutdown failed: %v\n", err)
		os.Exit(1)
	}

	// 3. Assertion: otlpmetrichttp.New with WithCompression(otlpmetrichttp.GzipCompression) transmits payloads with Content-Encoding gzip
	var (
		gzipMu      sync.Mutex
		gzipHeaders http.Header
		gzipBody    []byte
	)
	gzipServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		gzipMu.Lock()
		defer gzipMu.Unlock()
		gzipHeaders = r.Header.Clone()
		b, _ := io.ReadAll(r.Body)
		gzipBody = b
		w.Header().Set("Content-Type", "application/x-protobuf")
		w.WriteHeader(http.StatusOK)
	}))
	defer gzipServer.Close()

	gzipExp, err := otlpmetrichttp.New(
		ctx,
		otlpmetrichttp.WithHTTPClient(gzipServer.Client()),
		otlpmetrichttp.WithEndpointURL(gzipServer.URL+"/v1/metrics"),
		otlpmetrichttp.WithInsecure(),
		otlpmetrichttp.WithCompression(otlpmetrichttp.GzipCompression),
		otlpmetrichttp.WithRetry(otlpmetrichttp.RetryConfig{Enabled: false}),
	)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: New with Gzip compression failed: %v\n", err)
		os.Exit(1)
	}

	gzipReader := metric.NewPeriodicReader(gzipExp)
	gzipProvider := metric.NewMeterProvider(metric.WithReader(gzipReader))
	gzipMeter := gzipProvider.Meter("gzip-meter")
	gzipCounter, err := gzipMeter.Int64Counter("gzip_counter")
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: Int64Counter failed: %v\n", err)
		os.Exit(1)
	}
	gzipCounter.Add(ctx, 100)

	if err := gzipProvider.ForceFlush(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: gzipProvider.ForceFlush failed: %v\n", err)
		os.Exit(1)
	}
	_ = gzipProvider.Shutdown(ctx)

	gzipMu.Lock()
	if enc := gzipHeaders.Get("Content-Encoding"); enc != "gzip" {
		gzipMu.Unlock()
		fmt.Fprintf(os.Stderr, "FAIL: expected Content-Encoding gzip, got %q\n", enc)
		os.Exit(1)
	}
	if len(gzipBody) < 2 || !bytes.Equal(gzipBody[:2], []byte{0x1f, 0x8b}) {
		gzipMu.Unlock()
		fmt.Fprintf(os.Stderr, "FAIL: request body does not have gzip magic header (0x1f, 0x8b)\n")
		os.Exit(1)
	}
	gzipMu.Unlock()

	// 4. Assertion: otlpmetrichttp.New exporter returns an error when the export endpoint returns a non-2xx status code
	errServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
	}))
	defer errServer.Close()

	errExp, err := otlpmetrichttp.New(
		ctx,
		otlpmetrichttp.WithHTTPClient(errServer.Client()),
		otlpmetrichttp.WithEndpointURL(errServer.URL+"/v1/metrics"),
		otlpmetrichttp.WithInsecure(),
		otlpmetrichttp.WithRetry(otlpmetrichttp.RetryConfig{Enabled: false}),
	)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: New for error server failed: %v\n", err)
		os.Exit(1)
	}

	var rm metricdata.ResourceMetrics
	exportErr := errExp.Export(ctx, &rm)
	if exportErr == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected Export error on 500 HTTP status, got nil\n")
		os.Exit(1)
	}
	_ = errExp.Shutdown(ctx)

	fmt.Println("All contract assertions passed successfully.")
}