Make FormatAnnotationsStep round-trippable

Author: Goooler

lib/src/main/java/com/diffplug/spotless/java/FormatAnnotationsStep.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2022-2023 DiffPlug
+ * Copyright 2022-2024 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,6 +26,7 @@
 
 import com.diffplug.spotless.FormatterFunc;
 import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.RoundedStep;
 
 /**
  * Some formatters put every annotation on its own line
@@ -36,7 +37,8 @@
  * <p>
  * Note: A type annotation is an annotation that is meta-annotated with {@code @Target({ElementType.TYPE_USE})}.
  */
-public final class FormatAnnotationsStep {
+public final class FormatAnnotationsStep implements RoundedStep {
+	private static final long serialVersionUID = 1L;
 
 	/**
 	 * Simple names of type annotations.
@@ -389,7 +391,7 @@ public final class FormatAnnotationsStep {
 
 			);
 
-	static final String NAME = "No line break between type annotation and type";
+	private static final String NAME = "No line break between type annotation and type";
 
 	public static FormatterStep create() {
 		return create(Collections.emptyList(), Collections.emptyList());
@@ -432,13 +434,13 @@ private static final class State implements Serializable {
 		}
 
 		FormatterFunc toFormatter() {
-			return unixStr -> fixupTypeAnnotations(unixStr);
+			return this::fixupTypeAnnotations;
 		}
 
 		/**
 		 * Removes line break between type annotations and the following type.
 		 *
-		 * @param the text of a Java file
+		 * @param unixStr the text of a Java file
 		 * @return corrected text of the Java file
 		 */
 		String fixupTypeAnnotations(String unixStr) {