diff --git a/jackson/src/test/java/org/baeldung/jackson/dtos/MyDtoNullKeySerializer.java b/jackson/src/test/java/org/baeldung/jackson/serialization/MyDtoNullKeySerializer.java
similarity index 89%
rename from jackson/src/test/java/org/baeldung/jackson/dtos/MyDtoNullKeySerializer.java
rename to jackson/src/test/java/org/baeldung/jackson/serialization/MyDtoNullKeySerializer.java
index ab8ac6249d..8219abaddf 100644
--- a/jackson/src/test/java/org/baeldung/jackson/dtos/MyDtoNullKeySerializer.java
+++ b/jackson/src/test/java/org/baeldung/jackson/serialization/MyDtoNullKeySerializer.java
@@ -1,4 +1,4 @@
-package org.baeldung.jackson.dtos;
+package org.baeldung.jackson.serialization;
 
 import java.io.IOException;
 
@@ -11,9 +11,7 @@ public class MyDtoNullKeySerializer extends JsonSerializer<Object> {
 
     @Override
     public void serialize(final Object value, final JsonGenerator jgen, final SerializerProvider provider) throws IOException, JsonProcessingException {
-
         jgen.writeFieldName("");
-
     }
 
 }
diff --git a/jackson/src/test/java/org/baeldung/jackson/test/JacksonSerializationIgnoreUnitTest.java b/jackson/src/test/java/org/baeldung/jackson/test/JacksonSerializationIgnoreUnitTest.java
index c973584f9b..d0e0426ff0 100644
--- a/jackson/src/test/java/org/baeldung/jackson/test/JacksonSerializationIgnoreUnitTest.java
+++ b/jackson/src/test/java/org/baeldung/jackson/test/JacksonSerializationIgnoreUnitTest.java
@@ -10,12 +10,12 @@ import java.util.Map;
 
 import org.baeldung.jackson.dtos.MyDto;
 import org.baeldung.jackson.dtos.MyDtoIncludeNonDefault;
-import org.baeldung.jackson.dtos.MyDtoNullKeySerializer;
 import org.baeldung.jackson.dtos.MyDtoWithFilter;
 import org.baeldung.jackson.dtos.MyMixInForString;
 import org.baeldung.jackson.dtos.ignore.MyDtoIgnoreField;
 import org.baeldung.jackson.dtos.ignore.MyDtoIgnoreFieldByName;
 import org.baeldung.jackson.dtos.ignore.MyDtoIgnoreNull;
+import org.baeldung.jackson.serialization.MyDtoNullKeySerializer;
 import org.junit.Test;
 
 import com.fasterxml.jackson.annotation.JsonInclude.Include;
@@ -187,6 +187,8 @@ public class JacksonSerializationIgnoreUnitTest {
         System.out.println(dtoAsString);
     }
 
+    // map
+
     @Test
     public final void givenIgnoringMapNullValue_whenWritingMapObjectWithNullValue_thenIgnored() throws JsonProcessingException {
         final ObjectMapper mapper = new ObjectMapper();