Issue Description

This is a sub-issue of [ISSUE #4981 ]
The nacos-naming module coverage rate is just 22%, Could you add more unit tests to nacos-naming module?

Anything else we need to know?

To-do list:

• Add unit tests for package com.alibaba.nacos.naming.cluster
• Add unit tests for package com.alibaba.nacos.naming.consistency.ehpemeral.distro.v2 Add unit tests to package com.alibaba.nacos.naming.consistency.ehpemeral.distro.v2 in nacos 2.0 #5143
• Add unit tests for package com.alibaba.nacos.naming.core Add unit tests to package com.alibaba.nacos.naming.core in nacos 2.0 #4983 @JackSun-Developer
• Add unit tests for package com.alibaba.nacos.naming.healthcheck Add unit tests to package com.alibaba.nacos.naming.healthcheck in nacos 2.0 #5096@XiaoShuangLee
• Add unit tests for package com.alibaba.nacos.naming.push
• Add unit tests for package com.alibaba.nacos.naming.remote
• Add unit tests for package com.alibaba.nacos.naming.push
• Add unit tests for package com.alibaba.nacos.naming.controllers Add unit tests to package com.alibaba.nacos.naming.controllers in nacos 2.0 #5519