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- [x] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: 3.0.3
* Operating System version: all
* Java version: all

### Steps to reproduce this issue

1. consumer config
`dubbo.registry.address=multiple://?reference-registry=zookeeper://127.0.0.1:2181,nacos://127.0.0.1:8848&child.zk=zookeeper://127.0.0.1:2181&child.nacos=nacos://127.0.0.1:8848`

If there is an exception, please attach the exception trace:

```
java.lang.UnsupportedOperationException: Current implementation does not support pagination query method.
	at org.apache.dubbo.registry.client.ServiceDiscovery.getInstances(ServiceDiscovery.java:175) ~[dubbo-3.0.3.jar:3.0.3]
	at org.apache.dubbo.registry.multiple.MultipleServiceDiscovery.getInstances(MultipleServiceDiscovery.java:119) ~[dubbo-3.0.3.jar:3.0.3]
	at org.apache.dubbo.registry.client.ServiceDiscovery.getInstances(ServiceDiscovery.java:157) ~[dubbo-3.0.3.jar:3.0.3]
	at org.apache.dubbo.registry.client.ServiceDiscovery.getInstances(ServiceDiscovery.java:130) ~[dubbo-3.0.3.jar:3.0.3]
	at org.apache.dubbo.registry.client.ServiceDiscoveryRegistry.subscribeURLs(ServiceDiscoveryRegistry.java:302) ~[dubbo-3.0.3.jar:3.0.3]
	at org.apache.dubbo.registry.client.ServiceDiscoveryRegistry$DefaultMappingListener.onEvent(ServiceDiscoveryRegistry.java:376) ~[dubbo-3.0.3.jar:3.0.3]
```

* The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.dubbo.registry.multiple;
import org.apache.dubbo.common.URL;
import org.apache.dubbo.common.constants.CommonConstants;
import org.apache.dubbo.common.utils.DefaultPage;
import org.apache.dubbo.common.utils.Page;
import org.apache.dubbo.registry.client.ServiceDiscovery;
import org.apache.dubbo.registry.client.ServiceDiscoveryFactory;
import org.apache.dubbo.registry.client.ServiceInstance;
import org.apache.dubbo.registry.client.event.ServiceInstancesChangedEvent;
import org.apache.dubbo.registry.client.event.listener.ServiceInstancesChangedListener;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Function;
public class MultipleServiceDiscovery implements ServiceDiscovery {