Polish javadoc

Signed-off-by: Tran Ngoc Nhan <ngocnhan.tran1996@gmail.com>

oauth2/oauth2-resource-server/src/main/java/org/springframework/security/oauth2/server/resource/introspection/OpaqueTokenIntrospector.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -16,8 +16,6 @@
 
 package org.springframework.security.oauth2.server.resource.introspection;
 
-import java.util.Map;
-
 import org.springframework.security.oauth2.core.OAuth2AuthenticatedPrincipal;
 
 /**
@@ -40,7 +38,7 @@ public interface OpaqueTokenIntrospector {
 	/**
 	 * Introspect and verify the given token, returning its attributes.
 	 *
-	 * Returning a {@link Map} is indicative that the token is valid.
+	 * Returning a {@link OAuth2AuthenticatedPrincipal} is indicative that the token is valid.
 	 * @param token the token to introspect
 	 * @return the token's attributes
 	 */