Upgrade to Tomcat 9.0.55, Undertow 2.2.13, RxJava 3.1.3, SmallRye Mutiny 1.2, Joda-Time 2.10.13, JRuby 9.2.20.1, HtmlUnit 2.55, Checkstyle 9.2

spring-websocket/src/main/java/org/springframework/web/socket/server/standard/TomcatRequestUpgradeStrategy.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -53,6 +53,7 @@ public class TomcatRequestUpgradeStrategy extends AbstractStandardUpgradeStrateg
 		return new String[] {"13"};
 	}
 
+	@SuppressWarnings("deprecation")  // for old doUpgrade variant in Tomcat 9.0.55
 	@Override
 	public void upgradeInternal(ServerHttpRequest request, ServerHttpResponse response,
 			@Nullable String selectedProtocol, List<Extension> selectedExtensions, Endpoint endpoint)