Polish

See gh-22598

spring-web/src/main/java/org/springframework/http/ReadOnlyHttpHeaders.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.
@@ -41,12 +41,14 @@ class ReadOnlyHttpHeaders extends HttpHeaders {
 	private MediaType cachedContentType;
 
 	@Nullable
-	private MediaType cachedAccept;
+	private List<MediaType> cachedAccept;
+
 
 	ReadOnlyHttpHeaders(HttpHeaders headers) {
 		super(headers.headers);
 	}
 
+
 	@Override
 	public MediaType getContentType() {
 		if (this.cachedContentType != null) {