diff --git a/documentation/examples/custom-sd/adapter/adapter.go b/documentation/examples/custom-sd/adapter/adapter.go
index 39cfea289..048a7be34 100644
--- a/documentation/examples/custom-sd/adapter/adapter.go
+++ b/documentation/examples/custom-sd/adapter/adapter.go
@@ -18,14 +18,15 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"github.com/go-kit/kit/log"
-	"github.com/go-kit/kit/log/level"
-	"github.com/prometheus/prometheus/discovery"
-	"github.com/prometheus/prometheus/discovery/targetgroup"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
+
+	"github.com/go-kit/kit/log"
+	"github.com/go-kit/kit/log/level"
+	"github.com/prometheus/prometheus/discovery"
+	"github.com/prometheus/prometheus/discovery/targetgroup"
 )
 
 type customSD struct {
diff --git a/documentation/examples/custom-sd/adapter/adapter_test.go b/documentation/examples/custom-sd/adapter/adapter_test.go
index 291f2e082..563e1c108 100644
--- a/documentation/examples/custom-sd/adapter/adapter_test.go
+++ b/documentation/examples/custom-sd/adapter/adapter_test.go
@@ -14,10 +14,11 @@
 package adapter
 
 import (
-	"github.com/prometheus/common/model"
-	"github.com/prometheus/prometheus/discovery/targetgroup"
 	"reflect"
 	"testing"
+
+	"github.com/prometheus/common/model"
+	"github.com/prometheus/prometheus/discovery/targetgroup"
 )
 
 // TestGenerateTargetGroups checks that the target is correctly generated.
@@ -141,7 +142,7 @@ func TestGenerateTargetGroups(t *testing.T) {
 		result := generateTargetGroups(testCase.targetGroup)
 
 		if !reflect.DeepEqual(result, testCase.expectedCustomSD) {
-			t.Errorf("%v :\nresult produced %v\nmismatch the expected customSD: %v",
+			t.Errorf("%q failed\ngot: %#v\nexpected: %v",
 				testCase.title,
 				result,
 				testCase.expectedCustomSD)