diff --git a/src/main/java/com/bunq/sdk/http/BunqHeader.java b/src/main/java/com/bunq/sdk/http/BunqHeader.java
index e7025429..5ab93ecc 100644
--- a/src/main/java/com/bunq/sdk/http/BunqHeader.java
+++ b/src/main/java/com/bunq/sdk/http/BunqHeader.java
@@ -13,12 +13,12 @@ public enum BunqHeader {
     clientEncryptionKey("X-Bunq-Client-Encryption-Key"),
     clientRequestId("X-Bunq-Client-Request-Id"),
     clientSignature("X-Bunq-Client-Signature"),
-    clientResponseId("X-Bunq-Client-Response-Id","Could not determine response id."),
-    geolocation("X-Bunq-Geolocation","0 0 0 0 000"),
-    language("X-Bunq-Language","en_US"),
-    region("X-Bunq-Region","nl_NL"),
+    clientResponseId("X-Bunq-Client-Response-Id", "Could not determine response id."),
+    geolocation("X-Bunq-Geolocation", "0 0 0 0 000"),
+    language("X-Bunq-Language", "en_US"),
+    region("X-Bunq-Region", "nl_NL"),
     serverSignature("X-Bunq-Server-Signature"),
-    userAgent("User-Agent","bunq-sdk-java/0.13.1");
+    userAgent("User-Agent", "bunq-sdk-java/0.13.1");
 
     private static final String PREFIX = "X-Bunq-";
 
@@ -77,8 +77,8 @@ public boolean isBunq() {
     }
 
     private String findKey(Collection<String> keys) {
-        for(String key:keys) {
-            if(this.equals(key)) {
+        for (String key:keys) {
+            if (this.equals(key)) {
                 return key;
             }
         }
diff --git a/src/main/java/com/bunq/sdk/http/BunqRequestBuilder.java b/src/main/java/com/bunq/sdk/http/BunqRequestBuilder.java
index 915023d7..d89ed3cb 100644
--- a/src/main/java/com/bunq/sdk/http/BunqRequestBuilder.java
+++ b/src/main/java/com/bunq/sdk/http/BunqRequestBuilder.java
@@ -88,7 +88,7 @@ private void addToAllHeader(String name,String value) {
    */
   @Override
   public BunqRequestBuilder header(String name, String value) {
-    addToAllHeader(name,value);
+    addToAllHeader(name, value);
 
     return (BunqRequestBuilder) super.header(name, value);
   }
@@ -98,7 +98,7 @@ public BunqRequestBuilder header(String name, String value) {
    */
   @Override
   public BunqRequestBuilder addHeader(String name, String value) {
-    addToAllHeader(name,value);
+    addToAllHeader(name, value);
 
     return (BunqRequestBuilder) super.addHeader(name, value);
   }
diff --git a/src/main/java/com/bunq/sdk/security/SecurityUtils.java b/src/main/java/com/bunq/sdk/security/SecurityUtils.java
index e5831f65..1e7f08d0 100644
--- a/src/main/java/com/bunq/sdk/security/SecurityUtils.java
+++ b/src/main/java/com/bunq/sdk/security/SecurityUtils.java
@@ -459,9 +459,9 @@ public static void validateResponseSignature(
         response.headers()
     );
     Signature signature = getSignatureInstance();
-    BunqBasicHeader headerServerSignature = BunqBasicHeader.get(BunqHeader.serverSignature,response);
+    BunqBasicHeader serverSignature = BunqBasicHeader.get(BunqHeader.serverSignature,response);
 
-    byte[] serverSignatureBase64Bytes = headerServerSignature.getValue().getBytes();
+    byte[] serverSignatureBase64Bytes = serverSignature.getValue().getBytes();
     byte[] serverSignatureDecoded = Base64.getDecoder().decode(serverSignatureBase64Bytes);
     verifyDataSigned(signature, keyPublicServer, responseBytes, serverSignatureDecoded);
   }
diff --git a/src/test/java/com/bunq/sdk/http/BunqHeaderTest.java b/src/test/java/com/bunq/sdk/http/BunqHeaderTest.java
index bed67ba3..e1e054d8 100644
--- a/src/test/java/com/bunq/sdk/http/BunqHeaderTest.java
+++ b/src/test/java/com/bunq/sdk/http/BunqHeaderTest.java
@@ -3,8 +3,6 @@
 import org.junit.Test;
 
 import java.util.*;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
 
 import static org.junit.Assert.*;
 
diff --git a/src/test/java/com/bunq/sdk/model/generated/endpoint/AttachmentPublicTest.java b/src/test/java/com/bunq/sdk/model/generated/endpoint/AttachmentPublicTest.java
index 48eca29f..866d34d2 100644
--- a/src/test/java/com/bunq/sdk/model/generated/endpoint/AttachmentPublicTest.java
+++ b/src/test/java/com/bunq/sdk/model/generated/endpoint/AttachmentPublicTest.java
@@ -10,6 +10,7 @@
 import java.io.File;
 import java.io.IOException;
 import java.util.HashMap;
+import java.util.Map;
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
@@ -37,11 +38,12 @@ private static byte[] getRequestBytes() {
   }
 
   private static String uploadFileAndGetUuid() {
-    HashMap<String, String> customHeaders = new HashMap<>();
-    BunqHeader.contentType.addTo(customHeaders,CONTENT_TYPE);
-    BunqHeader.attachmentDescription.addTo(customHeaders,ATTACHMENT_DESCRIPTION);
-    byte[] RequestBytes = getRequestBytes();
-    return AttachmentPublic.create(customHeaders, RequestBytes).getValue();
+    Map<String, String> customHeaders = new HashMap<>();
+
+    BunqHeader.contentType.addTo(customHeaders, CONTENT_TYPE);
+    BunqHeader.attachmentDescription.addTo(customHeaders, ATTACHMENT_DESCRIPTION);
+
+    return AttachmentPublic.create(customHeaders, getRequestBytes()).getValue();
   }
 
   /**