Is your feature request related to a problem? Please describe.
当我自定义model的时候，有没有方法可以为host、guest、arbiter 分别指定 parameter class？ 目前他们公用一个parameter class，如果我想让host、guest、arbiter处理不同的参数，目前的办法好像只有设置默认值？
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Is your feature request related to a problem? Please describe.
当我自定义model的时候，有没有方法可以为host、guest、arbiter 分别指定 parameter class？ 目前他们公用一个parameter class，如果我想让host、guest、arbiter处理不同的参数，目前的办法好像只有设置默认值？
Describe the solution you'd like
A clear and concise description of what you want to happen.
Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.
Additional context
Add any other context or screenshots about the feature request here.