Polishing.

Update since tags. Add missing Override annotation.

See #4070
Original pull request: #4242

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/AggregationVariable.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 the original author or authors.
+ * Copyright 2022-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,7 +23,7 @@ import org.springframework.util.ObjectUtils;
  * A special field that points to a variable {@code $$} expression.
  *
  * @author Christoph Strobl
- * @since 4.1
+ * @since 4.1.3
  */
 public interface AggregationVariable extends Field {
 
@@ -33,6 +33,7 @@ public interface AggregationVariable extends Field {
 	 * @return {@literal true} if the fields {@link #getName() name} does not match the defined {@link #getTarget()
 	 *         target}.
 	 */
+	@Override
 	default boolean isAliased() {
 		return !ObjectUtils.nullSafeEquals(getName(), getTarget());
 	}
@@ -42,6 +43,7 @@ public interface AggregationVariable extends Field {
 		return getTarget();
 	}
 
+	@Override
 	default boolean isInternal() {
 		return false;
 	}
@@ -50,7 +52,7 @@ public interface AggregationVariable extends Field {
 	 * Create a new {@link AggregationVariable} for the given name.
 	 * <p>
 	 * Variables start with {@code $$}. If not, the given value gets prefixed with {@code $$}.
-	 * 
+	 *
 	 * @param value must not be {@literal null}.
 	 * @return new instance of {@link AggregationVariable}.
 	 * @throws IllegalArgumentException if given value is {@literal null}.
@@ -127,4 +129,5 @@ public interface AggregationVariable extends Field {
 		var trimmed = variable.stripLeading();
 		return trimmed.startsWith(PREFIX) ? trimmed : (PREFIX + trimmed);
 	}
+
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/Fields.java

@@ -67,7 +67,7 @@ public final class Fields implements Iterable<Field> {
 
 		Assert.notNull(names, "Field names must not be null");
 
-		List<Field> fields = new ArrayList<Field>();
+		List<Field> fields = new ArrayList<>();
 
 		for (String name : names) {
 			fields.add(field(name));
@@ -114,7 +114,7 @@ public final class Fields implements Iterable<Field> {
 
 	private static List<Field> verify(List<Field> fields) {
 
-		Map<String, Field> reference = new HashMap<String, Field>();
+		Map<String, Field> reference = new HashMap<>();
 
 		for (Field field : fields) {
 
@@ -133,7 +133,7 @@ public final class Fields implements Iterable<Field> {
 
 	private Fields(Fields existing, Field tail) {
 
-		this.fields = new ArrayList<Field>(existing.fields.size() + 1);
+		this.fields = new ArrayList<>(existing.fields.size() + 1);
 		this.fields.addAll(existing.fields);
 		this.fields.add(tail);
 	}
@@ -253,10 +253,12 @@ public final class Fields implements Iterable<Field> {
 			return dollarIndex == -1 ? source : source.substring(dollarIndex + 1);
 		}
 
+		@Override
 		public String getName() {
 			return name;
 		}
 
+		@Override
 		public String getTarget() {
 
 			if (isLocalVar() || pointsToDBRefId()) {

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/ReplaceRootOperation.java

@@ -21,7 +21,6 @@ import java.util.Collections;
 import java.util.List;
 
 import org.bson.Document;
-
 import org.springframework.data.mongodb.core.aggregation.ExposedFields.ExposedField;
 import org.springframework.expression.spel.ast.Projection;
 import org.springframework.util.Assert;
@@ -431,6 +430,7 @@ public class ReplaceRootOperation implements FieldsExposingAggregationOperation
 		 * @param context will never be {@literal null}.
 		 * @return never {@literal null}.
 		 */
+		@Override
 		Document toDocument(AggregationOperationContext context);
 	}
 

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/AggregationVariableUnitTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 the original author or authors.
+ * Copyright 2022-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,8 @@ import org.junit.jupiter.api.Test;
 import org.mockito.Mockito;
 
 /**
+ * Unit tests for {@link AggregationVariable}.
+ *
  * @author Christoph Strobl
  */
 class AggregationVariableUnitTests {