Make MultipartResolutionDelegate final (aligned with other delegates)

spring-web/src/main/java/org/springframework/web/multipart/support/MultipartResolutionDelegate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -38,7 +38,7 @@ import org.springframework.web.util.WebUtils;
  * @author Juergen Hoeller
  * @since 4.3
  */
-public abstract class MultipartResolutionDelegate {
+public final class MultipartResolutionDelegate {
 
 	/**
 	 * Indicates an unresolvable value.
@@ -46,6 +46,10 @@ public abstract class MultipartResolutionDelegate {
 	public static final Object UNRESOLVABLE = new Object();
 
 
+	private MultipartResolutionDelegate() {
+	}
+
+
 	@Nullable
 	public static MultipartRequest resolveMultipartRequest(NativeWebRequest webRequest) {
 		MultipartRequest multipartRequest = webRequest.getNativeRequest(MultipartRequest.class);