You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: import_product_sets_test.go
    path of file: ./repos/golang-samples/vision/product_search
    
    the code of the file until where you have to start completion: // Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package productsearch

import (
	"bytes"
	"strings"
	"testing"

	"github.com/GoogleCloudPlatform/golang-samples/internal/testutil"
)

func TestImportProductSets(t *testing.T) {
	tc := testutil.SystemTest(t)

	const location = "us-west1"
	const gcsURI = "gs://cloud-samples-data/
    
func TestImportProductSets(t *testing.T) {
	tc := testutil.SystemTest(t)

	const location = "us-west1"
	const gcsURI = "gs://cloud-samples-data/vision/product_search/product_sets.csv"
	const productSetID = "fake_product_set_id_for_testing"
	const productID1 = "fake_product_id_for_testing_1"
	const productID2 = "fake_product_id_for_testing_2"
	const imageURI1 = "shoes_1.jpg"
	const imageURI2 = "shoes_2.jpg"

	var buf bytes.Buffer

	// Ensure re-used resource names don't exist prior to test start.
	if err := getProductSet(&buf, tc.ProjectID, location, productSetID); err == nil {
		deleteProductSet(&buf, tc.ProjectID, location, productSetID)
	}
	if err := getProduct(&buf, tc.ProjectID, location, productID1); err == nil {
		deleteProduct(&buf, tc.ProjectID, location, productID1)
	}
	if err := getProduct(&buf, tc.ProjectID, location, productID2); err == nil {
		deleteProduct(&buf, tc.ProjectID, location, productID2)
	}

	buf.Reset()

	// Import product set.
	if err := importProductSets(&buf, tc.ProjectID, location, gcsURI); err != nil {
		t.Fatalf("importProductSets: %v", err)
	}

	// Check if the product set exists now.
	buf.Reset()
	if err := listProductSets(&buf, tc.ProjectID, location); err != nil {
		t.Fatalf("listProductSets: %v", err)
	}
	if got := buf.String(); !strings.Contains(got, productSetID) {
		t.Errorf("Product set ID %s does not exist", productSetID)
	}

	// Check if the products exist.
	buf.Reset()
	if err := listProducts(&buf, tc.ProjectID, location); err != nil {
		t.Fatalf("listProducts: %v", err)
	}
	if got := buf.String(); !strings.Contains(got, productID1) || !strings.Contains(got, productID2) {
		t.Errorf("Product IDs %s %s do not exist", productID1, productID2)
	}

	// Check if the products are in the product set.
	buf.Reset()
	if err := listProductsInProductSet(&buf, tc.ProjectID, location, productSetID); err != nil {
		t.Fatalf("listProductsInProductSet: %v", err)
	}
	if got := buf.String(); !strings.Contains(got, productID1) || !strings.Contains(got, productID2) {
		t.Errorf("Product IDs %s %s do not exist in product set", productID1, productID2)
	}

	// check if the reference images exsit.
	buf.Reset()
	if err := listReferenceImages(&buf, tc.ProjectID, location, productID1); err != nil {
		t.Fatalf("listReferenceImages: %v", err)
	}
	if got := buf.String(); !strings.Contains(got, imageURI1) {
		t.Errorf("Reference image uri %s does not exist in product set", imageURI1)
	}

	buf.Reset()
	if err := listReferenceImages(&buf, tc.ProjectID, location, productID2); err != nil {
		t.Fatalf("listReferenceImages: %v", err)
	}
	if got := buf.String(); !strings.Contains(got, imageURI2) {
		t.Errorf("Reference image uri %s does not exist in product set", imageURI2)
	}

	// Clean up.
	deleteProduct(&buf, tc.ProjectID, location, productID1)
	deleteProduct(&buf, tc.ProjectID, location, productID2)
	deleteProductSet(&buf, tc.ProjectID, location, productSetID)
}