Polishing.

See #4139
Original pull request: #4182.

Author: christophstrobl

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

@@ -55,6 +55,14 @@ public static Bottom bottom() {
 			return new Bottom(Collections.emptyMap());
 		}
 
+		/**
+		 * @param numberOfResults Limits the number of returned elements to the given value.
+		 * @return new instance of {@link Bottom}.
+		 */
+		public static Bottom bottom(int numberOfResults) {
+			return bottom().limit(numberOfResults);
+		}
+
 		/**
 		 * Limits the number of returned elements to the given value.
 		 *
@@ -239,14 +247,14 @@ protected First(Object value) {
 		 * @return new instance of {@link First}.
 		 */
 		public static First first() {
-			return new First(Collections.emptyMap()).limit(1);
+			return new First(Collections.emptyMap());
 		}
 
 		/**
 		 * @return new instance of {@link First}.
 		 */
 		public static First first(int numberOfResults) {
-			return new First(Collections.emptyMap()).limit(numberOfResults);
+			return first().limit(numberOfResults);
 		}
 
 		/**
@@ -333,14 +341,14 @@ protected Last(Object value) {
 		 * @return new instance of {@link Last}.
 		 */
 		public static Last last() {
-			return new Last(Collections.emptyMap()).limit(1);
+			return new Last(Collections.emptyMap());
 		}
 
 		/**
 		 * @return new instance of {@link Last}.
 		 */
 		public static Last last(int numberOfResults) {
-			return new Last(Collections.emptyMap()).limit(numberOfResults);
+			return last().limit(numberOfResults);
 		}
 
 		/**

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

@@ -74,8 +74,8 @@ void bottomMapsFieldNamesCorrectly() {
 	@Test // GH-4139
 	void bottomNRenderedCorrectly() {
 
-		Document document = SelectionOperators.Bottom.bottom().output(Fields.fields("playerId", "score"))
-				.sortBy(Sort.by(Direction.DESC, "score")).limit(3).toDocument(Aggregation.DEFAULT_CONTEXT);
+		Document document = SelectionOperators.Bottom.bottom(3).output(Fields.fields("playerId", "score"))
+				.sortBy(Sort.by(Direction.DESC, "score")).toDocument(Aggregation.DEFAULT_CONTEXT);
 
 		assertThat(document).isEqualTo(Document.parse("""
 				{
@@ -114,8 +114,8 @@ void topMapsFieldNamesCorrectly() {
 	@Test // GH-4139
 	void topNRenderedCorrectly() {
 
-		Document document = SelectionOperators.Top.top().output(Fields.fields("playerId", "score"))
-				.sortBy(Sort.by(Direction.DESC, "score")).limit(3).toDocument(Aggregation.DEFAULT_CONTEXT);
+		Document document = SelectionOperators.Top.top(3).output(Fields.fields("playerId", "score"))
+				.sortBy(Sort.by(Direction.DESC, "score")).toDocument(Aggregation.DEFAULT_CONTEXT);
 
 		assertThat(document).isEqualTo(Document.parse("""
 				{