diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java
index d41decf3e..bcb9575b9 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java
@@ -171,8 +171,8 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 
 		Assert.notNull(path, "ObjectPath must not be null");
 
-		return new ConversionContext(conversions, path, this::readDocument, this::readCollectionOrArray, this::readMap, this::readDBRef,
-				this::getPotentiallyConvertedSimpleRead);
+		return new ConversionContext(conversions, path, this::readDocument, this::readCollectionOrArray, this::readMap,
+				this::readDBRef, this::getPotentiallyConvertedSimpleRead);
 	}
 
 	/**
@@ -527,7 +527,8 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 			return;
 		}
 
-		if (property.isDocumentReference() || (!property.isDbReference() && property.findAnnotation(Reference.class) != null)) {
+		if (property.isDocumentReference()
+				|| (!property.isDbReference() && property.findAnnotation(Reference.class) != null)) {
 
 			// quite unusual but sounds like worth having?
 
@@ -595,13 +596,13 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 
 		Assert.notNull(referringProperty, "Cannot create DocumentReference. The referringProperty must not be null!");
 
-			if (referringProperty.isDbReference()) {
-				return () -> toDBRef(source, referringProperty);
-			}
+		if (referringProperty.isDbReference()) {
+			return () -> toDBRef(source, referringProperty);
+		}
 
-			if (referringProperty.isDocumentReference() || referringProperty.findAnnotation(Reference.class) != null) {
-				return createDocumentPointer(source, referringProperty);
-			}
+		if (referringProperty.isDocumentReference() || referringProperty.findAnnotation(Reference.class) != null) {
+			return createDocumentPointer(source, referringProperty);
+		}
 
 		throw new IllegalArgumentException("The referringProperty is neither a DBRef nor a document reference");
 	}
@@ -612,7 +613,7 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 			return () -> source;
 		}
 
-		if(source instanceof DocumentPointer) {
+		if (source instanceof DocumentPointer) {
 			return (DocumentPointer<?>) source;
 		}
 
@@ -622,7 +623,8 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 		}
 
 		if (ClassUtils.isAssignableValue(referringProperty.getAssociationTargetType(), source)) {
-			return documentPointerFactory.computePointer(mappingContext, referringProperty, source, referringProperty.getActualType());
+			return documentPointerFactory.computePointer(mappingContext, referringProperty, source,
+					referringProperty.getActualType());
 		}
 
 		return () -> source;
@@ -1978,9 +1980,10 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 		private final ContainerValueConverter<DBRef> dbRefConverter;
 		private final ValueConverter<Object> elementConverter;
 
-		ConversionContext(org.springframework.data.convert.CustomConversions customConversions, ObjectPath path, ContainerValueConverter<Bson> documentConverter,
-				ContainerValueConverter<Collection<?>> collectionConverter, ContainerValueConverter<Bson> mapConverter,
-				ContainerValueConverter<DBRef> dbRefConverter, ValueConverter<Object> elementConverter) {
+		ConversionContext(org.springframework.data.convert.CustomConversions customConversions, ObjectPath path,
+				ContainerValueConverter<Bson> documentConverter, ContainerValueConverter<Collection<?>> collectionConverter,
+				ContainerValueConverter<Bson> mapConverter, ContainerValueConverter<DBRef> dbRefConverter,
+				ValueConverter<Object> elementConverter) {
 
 			this.conversions = customConversions;
 			this.path = path;
@@ -2052,8 +2055,8 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 
 			Assert.notNull(currentPath, "ObjectPath must not be null");
 
-			return new ConversionContext(conversions, currentPath, documentConverter, collectionConverter, mapConverter, dbRefConverter,
-					elementConverter);
+			return new ConversionContext(conversions, currentPath, documentConverter, collectionConverter, mapConverter,
+					dbRefConverter, elementConverter);
 		}
 
 		public ObjectPath getPath() {
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java
index 441b8e334..2009b5314 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/convert/MappingMongoConverterUnitTests.java
@@ -30,7 +30,6 @@ import java.time.LocalDateTime;
 import java.time.temporal.ChronoUnit;
 import java.util.*;
 
-import org.assertj.core.api.Assertions;
 import org.bson.types.Code;
 import org.bson.types.Decimal128;
 import org.bson.types.ObjectId;
@@ -42,6 +41,7 @@ import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.junit.jupiter.MockitoExtension;
+
 import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.beans.ConversionNotSupportedException;
 import org.springframework.beans.factory.annotation.Value;
@@ -529,7 +529,7 @@ class MappingMongoConverterUnitTests {
 	}
 
 	@Test
-	public void convertsObjectsIfNecessary() {
+	void convertsObjectsIfNecessary() {
 
 		ObjectId id = new ObjectId();
 		assertThat(converter.convertToMongoType(id)).isEqualTo(id);
@@ -2113,21 +2113,21 @@ class MappingMongoConverterUnitTests {
 	}
 
 	@Test // DATAMONGO-2479
-	public void entityCallbacksAreNotSetByDefault() {
-		Assertions.assertThat(ReflectionTestUtils.getField(converter, "entityCallbacks")).isNull();
+	void entityCallbacksAreNotSetByDefault() {
+		assertThat(ReflectionTestUtils.getField(converter, "entityCallbacks")).isNull();
 	}
 
 	@Test // DATAMONGO-2479
-	public void entityCallbacksShouldBeInitiatedOnSettingApplicationContext() {
+	void entityCallbacksShouldBeInitiatedOnSettingApplicationContext() {
 
 		ApplicationContext ctx = new StaticApplicationContext();
 		converter.setApplicationContext(ctx);
 
-		Assertions.assertThat(ReflectionTestUtils.getField(converter, "entityCallbacks")).isNotNull();
+		assertThat(ReflectionTestUtils.getField(converter, "entityCallbacks")).isNotNull();
 	}
 
 	@Test // DATAMONGO-2479
-	public void setterForEntityCallbackOverridesContextInitializedOnes() {
+	void setterForEntityCallbackOverridesContextInitializedOnes() {
 
 		ApplicationContext ctx = new StaticApplicationContext();
 		converter.setApplicationContext(ctx);
@@ -2135,11 +2135,11 @@ class MappingMongoConverterUnitTests {
 		EntityCallbacks callbacks = EntityCallbacks.create();
 		converter.setEntityCallbacks(callbacks);
 
-		Assertions.assertThat(ReflectionTestUtils.getField(converter, "entityCallbacks")).isSameAs(callbacks);
+		assertThat(ReflectionTestUtils.getField(converter, "entityCallbacks")).isSameAs(callbacks);
 	}
 
 	@Test // DATAMONGO-2479
-	public void setterForApplicationContextShouldNotOverrideAlreadySetEntityCallbacks() {
+	void setterForApplicationContextShouldNotOverrideAlreadySetEntityCallbacks() {
 
 		EntityCallbacks callbacks = EntityCallbacks.create();
 		ApplicationContext ctx = new StaticApplicationContext();
@@ -2147,11 +2147,11 @@ class MappingMongoConverterUnitTests {
 		converter.setEntityCallbacks(callbacks);
 		converter.setApplicationContext(ctx);
 
-		Assertions.assertThat(ReflectionTestUtils.getField(converter, "entityCallbacks")).isSameAs(callbacks);
+		assertThat(ReflectionTestUtils.getField(converter, "entityCallbacks")).isSameAs(callbacks);
 	}
 
 	@Test // DATAMONGO-2479
-	public void resolveDBRefMapValueShouldInvokeCallbacks() {
+	void resolveDBRefMapValueShouldInvokeCallbacks() {
 
 		AfterConvertCallback<Person> afterConvertCallback = spy(new ReturningAfterConvertCallback());
 		converter.setEntityCallbacks(EntityCallbacks.create(afterConvertCallback));
@@ -2168,7 +2168,7 @@ class MappingMongoConverterUnitTests {
 	}
 
 	@Test // DATAMONGO-2300
-	public void readAndConvertDBRefNestedByMapCorrectly() {
+	void readAndConvertDBRefNestedByMapCorrectly() {
 
 		org.bson.Document cluster = new org.bson.Document("_id", 100L);
 		DBRef dbRef = new DBRef("clusters", 100L);
@@ -2434,7 +2434,6 @@ class MappingMongoConverterUnitTests {
 	@Test // GH-3660
 	void usesCustomConverterForMapTypesOnWrite() {
 
-
 		converter = new MappingMongoConverter(resolver, mappingContext);
 		converter.setCustomConversions(MongoCustomConversions.create(it -> {
 			it.registerConverter(new TypeImplementingMapToDocumentConverter());
@@ -2521,7 +2520,6 @@ class MappingMongoConverterUnitTests {
 		assertThat(target.typeImplementingMap).isEqualTo(new TypeImplementingMap("one", 2));
 	}
 
-
 	static class GenericType<T> {
 		T content;
 	}
@@ -3098,7 +3096,7 @@ class MappingMongoConverterUnitTests {
 		String val1;
 		int val2;
 
-		public TypeImplementingMap(String val1, int val2) {
+		TypeImplementingMap(String val1, int val2) {
 			this.val1 = val1;
 			this.val2 = val2;
 		}