So far -- fix this message

hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/BackupClientFactory.java

@@ -25,6 +25,7 @@ import org.apache.hadoop.hbase.backup.impl.IncrementalTableBackupClient;
 import org.apache.hadoop.hbase.backup.impl.TableBackupClient;
 import org.apache.hadoop.hbase.client.Connection;
 
+@InterfaceAudience.Private
 public class BackupClientFactory {
 
   public static TableBackupClient create (Connection conn, String backupId, BackupRequest request)

hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryComparator.java

@@ -33,6 +33,7 @@ import org.apache.hadoop.hbase.shaded.com.google.protobuf.InvalidProtocolBufferE
 /**
  * A binary comparator which lexicographically compares against the specified
  * byte array using {@link org.apache.hadoop.hbase.util.Bytes#compareTo(byte[], byte[])}.
+ * @since 2.0.0
  */
 @InterfaceAudience.Public
 public class BinaryComparator extends org.apache.hadoop.hbase.filter.ByteArrayComparable {

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java

@@ -89,6 +89,7 @@ import org.apache.hadoop.security.token.TokenSelector;
  * outside the lock in {@link Call} and {@link HBaseRpcController} which means the implementations
  * of the callbacks are free to hold any lock.</li>
  * </ul>
+ * @since 2.0.0
  */
 @InterfaceAudience.Private
 public abstract class AbstractRpcClient<T extends RpcConnection> implements RpcClient {

hbase-client/src/main/java/org/apache/hadoop/hbase/security/AbstractHBaseSaslRpcClient.java

@@ -42,6 +42,7 @@ import org.apache.hadoop.security.token.TokenIdentifier;
 /**
  * A utility class that encapsulates SASL logic for RPC client. Copied from
  * <code>org.apache.hadoop.security</code>
+ * @since 2.0.0
  */
 @InterfaceAudience.Private
 public abstract class AbstractHBaseSaslRpcClient {

hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlUtil.java

@@ -37,6 +37,9 @@ import com.google.protobuf.ByteString;
 import com.google.protobuf.RpcController;
 import com.google.protobuf.ServiceException;
 
+/**
+ * @since 2.0.0
+ */
 @InterfaceAudience.Private
 public class AccessControlUtil {
   private AccessControlUtil() {}