Protecting Open XML Document using EPP Plus library

I am using EPP Plus library to create my excel documents. I would like to开发者_运维知识库 protect my document/cells. I can lock my cells but I am unable to lock my document. Can anybody please assist me with how to do this.

Thanks

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Well I resolved it. It was pretty easy. Each cell has property locked in style. So basically we need to unlock cells which are need to be editable. then we lock the whole sheet. It does the trick :)