Polishing.

See #3720
Original pull request: #3745.

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

@@ -252,7 +252,8 @@ public class ConditionalOperators {
 		/**
 		 * Creates new {@link IfNull}.
 		 *
-		 * @param fieldReference the field to check for a {@literal null} value, field reference must not be {@literal null}.
+		 * @param fieldReference the field to check for a {@literal null} value, field reference must not be
+		 *          {@literal null}.
 		 * @return never {@literal null}.
 		 */
 		public static ThenBuilder ifNull(String fieldReference) {
@@ -283,8 +284,8 @@ public class ConditionalOperators {
 
 			List<Object> list = new ArrayList<Object>();
 
-			if(condition instanceof Collection) {
-				for(Object val : ((Collection)this.condition)) {
+			if (condition instanceof Collection) {
+				for (Object val : ((Collection) this.condition)) {
 					list.add(mapCondition(val, context));
 				}
 			} else {
@@ -346,7 +347,8 @@ public class ConditionalOperators {
 		public interface OrBuilder {
 
 			/**
-			 * @param fieldReference the field to check for a {@literal null} value, field reference must not be {@literal null}.
+			 * @param fieldReference the field to check for a {@literal null} value, field reference must not be
+			 *          {@literal null}.
 			 * @return the {@link ThenBuilder}
 			 */
 			ThenBuilder orIfNull(String fieldReference);
@@ -499,7 +501,7 @@ public class ConditionalOperators {
 		public static Switch switchCases(List<CaseOperator> conditions) {
 
 			Assert.notNull(conditions, "Conditions must not be null!");
-			return new Switch(Collections.<String, Object>singletonMap("branches", new ArrayList<CaseOperator>(conditions)));
+			return new Switch(Collections.<String, Object> singletonMap("branches", new ArrayList<CaseOperator>(conditions)));
 		}
 
 		/**
@@ -902,8 +904,7 @@ public class ConditionalOperators {
 			private @Nullable Object condition;
 			private @Nullable Object thenValue;
 
-			private ConditionalExpressionBuilder() {
-			}
+			private ConditionalExpressionBuilder() {}
 
 			/**
 			 * Creates a new builder for {@link Cond}.

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

@@ -22,9 +22,11 @@ import org.bson.Document;
 import org.junit.jupiter.api.Test;
 
 /**
+ * Unit tests for {@link ConditionalOperators}.
+ *
  * @author Christoph Strobl
  */
-public class ConditionalOperatorsUnitTests {
+class ConditionalOperatorsUnitTests {
 
 	@Test // GH-3720
 	void rendersIfNullWithMultipleConditionalValuesCorrectly() {