diff --git a/google/internal/externalaccount/aws.go b/google/internal/externalaccount/aws.go
index d505cf8..a061345 100644
--- a/google/internal/externalaccount/aws.go
+++ b/google/internal/externalaccount/aws.go
@@ -34,20 +34,20 @@ func NewRequestSigner(regionName string, awsSecurityCredentials map[string]strin
 }
 
 const (
-// AWS Signature Version 4 signing algorithm identifier.
+	// AWS Signature Version 4 signing algorithm identifier.
 	awsAlgorithm = "AWS4-HMAC-SHA256"
 
-// The termination string for the AWS credential scope value as defined in
-// https://docs.aws.amazon.com/general/latest/gr/sigv4-create-string-to-sign.html
+	// The termination string for the AWS credential scope value as defined in
+	// https://docs.aws.amazon.com/general/latest/gr/sigv4-create-string-to-sign.html
 	awsRequestType = "aws4_request"
 
-// The AWS authorization header name for the security session token if available.
+	// The AWS authorization header name for the security session token if available.
 	awsSecurityTokenHeader = "x-amz-security-token"
 
-// The AWS authorization header name for the auto-generated date.
+	// The AWS authorization header name for the auto-generated date.
 	awsDateHeader = "x-amz-date"
 
-	awsTimeFormatLong = "20060102T150405Z"
+	awsTimeFormatLong  = "20060102T150405Z"
 	awsTimeFormatShort = "20060102"
 )
 
@@ -218,14 +218,14 @@ func (rs *RequestSigner) generateAuthentication(req *http.Request, timestamp tim
 		serviceName = splitHost[0]
 	}
 
-	credentialScope := fmt.Sprintf("%s/%s/%s/%s",dateStamp, rs.RegionName, serviceName, awsRequestType)
+	credentialScope := fmt.Sprintf("%s/%s/%s/%s", dateStamp, rs.RegionName, serviceName, awsRequestType)
 
 	requestString, err := canonicalRequest(req, canonicalHeaderColumns, canonicalHeaderData)
 	if err != nil {
 		return "", err
 	}
 	requestHash, err := getSha256([]byte(requestString))
-	if err != nil{
+	if err != nil {
 		return "", err
 	}
 
@@ -241,7 +241,7 @@ func (rs *RequestSigner) generateAuthentication(req *http.Request, timestamp tim
 		dateStamp, rs.RegionName, serviceName, awsRequestType, stringToSign,
 	} {
 		signingKey, err = getHmacSha256(signingKey, []byte(signingInput))
-		if err != nil{
+		if err != nil {
 			return "", err
 		}
 	}
diff --git a/google/internal/externalaccount/aws_test.go b/google/internal/externalaccount/aws_test.go
index d1432dc..d5e06a1 100644
--- a/google/internal/externalaccount/aws_test.go
+++ b/google/internal/externalaccount/aws_test.go
@@ -14,7 +14,8 @@ import (
 
 var defaultTime = time.Date(2011, 9, 9, 23, 36, 0, 0, time.UTC)
 var secondDefaultTime = time.Date(2020, 8, 11, 6, 55, 22, 0, time.UTC)
-func setTime(testTime time.Time) (func() time.Time) {
+
+func setTime(testTime time.Time) func() time.Time {
 	return func() time.Time {
 		return testTime
 	}
@@ -72,7 +73,7 @@ func TestAwsV4Signature_GetRequest(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -90,7 +91,7 @@ func TestAwsV4Signature_GetRequestWithRelativePath(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -108,7 +109,7 @@ func TestAwsV4Signature_GetRequestWithDotPath(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -126,7 +127,7 @@ func TestAwsV4Signature_GetRequestWithPointlessDotPath(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -144,7 +145,7 @@ func TestAwsV4Signature_GetRequestWithUtf8Path(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -162,7 +163,7 @@ func TestAwsV4Signature_GetRequestWithDuplicateQuery(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -180,7 +181,7 @@ func TestAwsV4Signature_GetRequestWithMisorderedQuery(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -198,7 +199,7 @@ func TestAwsV4Signature_GetRequestWithUtf8Query(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -218,7 +219,7 @@ func TestAwsV4Signature_PostRequest(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -238,7 +239,7 @@ func TestAwsV4Signature_PostRequestWithCapitalizedHeaderValue(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -258,7 +259,7 @@ func TestAwsV4Signature_PostRequestPhfft(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -278,7 +279,7 @@ func TestAwsV4Signature_PostRequestWithBody(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -296,7 +297,7 @@ func TestAwsV4Signature_PostRequestWithQueryString(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(defaultTime)
 
 	testRequestSigner(t, defaultRequestSigner, input, output)
@@ -314,7 +315,7 @@ func TestAwsV4Signature_GetRequestWithSecurityToken(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(secondDefaultTime)
 
 	testRequestSigner(t, requestSignerWithToken, input, output)
@@ -332,7 +333,7 @@ func TestAwsV4Signature_PostRequestWithSecurityToken(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(secondDefaultTime)
 
 	testRequestSigner(t, requestSignerWithToken, input, output)
@@ -355,7 +356,7 @@ func TestAwsV4Signature_PostRequestWithSecurityTokenAndAdditionalHeaders(t *test
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(secondDefaultTime)
 
 	testRequestSigner(t, requestSignerWithToken, input, output)
@@ -377,7 +378,7 @@ func TestAwsV4Signature_PostRequestWithAmzDateButNoSecurityToken(t *testing.T) {
 	}
 
 	oldNow := now
-	defer func() {now = oldNow}()
+	defer func() { now = oldNow }()
 	now = setTime(secondDefaultTime)
 
 	testRequestSigner(t, requestSigner, input, output)