<!-- If you need to report a security issue please visit https://github.com/apache/dubbo/security/policy -->

- [ ] 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: 3.1.1
* Operating System version: macosx
* Java version: 17

### Steps to reproduce this issue
provider:
```
    <dubbo:protocol name="dubbo" serialization="fastjson2" port="20880"></dubbo:protocol>
    <dubbo:service protocol="dubbo" serialization="fastjson2" version="${dubbo.version:3.1.1}" loadbalance="roundrobin" interface="cn.app.service.TestService" timeout="50" registry="dubboRegistry"
                   ref="testService"/>
```
consumer:
The serialization method remains the same as hesian2
![image](https://user-images.githubusercontent.com/19943636/197732272-91b6260a-b23c-4e35-9ac1-980ce8bf75bd.png)
![image](https://user-images.githubusercontent.com/19943636/197732300-eb5fccec-0de0-4211-b240-a0fbd008c1ad.png)

Self-declared dubbo interfaces are normal
![image](https://user-images.githubusercontent.com/19943636/197733004-42fa2710-3ba3-4969-a302-b1706938c9e6.png)


Pls. provide [GitHub address] to reproduce this issue.

### Expected Behavior

<!-- What do you expect from the above steps？-->

### Actual Behavior

<!-- What actually happens? -->

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

```
Just put your stack trace here!
```

}
    @Test
    public void testToMap2() throws Exception {
        Assertions.assertThrows(IllegalArgumentException.class, () -> toMap("a", "b", "c"));
    }
    @Test
    public void testIsEmpty() throws Exception {
        assertThat(isEmpty(null), is(true));
        assertThat(isEmpty(new HashSet()), is(true));
        assertThat(isEmpty(emptyList()), is(true));
    }
    @Test
    public void testIsNotEmpty() throws Exception {
        assertThat(isNotEmpty(singleton("a")), is(true));
    }
    @Test
    public void testOfSet() {
        Set<String> set = ofSet();
        assertEquals(emptySet(), set);
        set = ofSet(((String[]) null));
        assertEquals(emptySet(), set);
        set = ofSet("A", "B", "C");
        Set<String> expectedSet = new LinkedHashSet<>();
        expectedSet.add("A");
        expectedSet.add("B");
        expectedSet.add("C");
        assertEquals(expectedSet, set);
    }
}