HADOOP-14784. [KMS] Improve KeyAuthorizationKeyProvider#toString(). Contributed by Yeliang Cang.

Reviewed-by: Dinesh Chitlangia <dchitlangia@cloudera.com>

hadoop-common-project/hadoop-kms/src/main/java/org/apache/hadoop/crypto/key/kms/server/KeyAuthorizationKeyProvider.java

@@ -402,7 +402,7 @@ public class KeyAuthorizationKeyProvider extends KeyProviderCryptoExtension {
 
   @Override
   public String toString() {
-    return provider.toString();
+    return this.getClass().getName()+": "+provider.toString();
   }
 
 }