How to prevent selected fields from being updated in Y.js?

Question

Imagine object like this

const project = { 
  editors:{'me@stack.com':'owner', 'they@stack.com':'manager' },
  title:'myStackProject',
  article:'I love to ask questions'
}

In my case managers can't edit title and rights but they can edit article. So the problem is how to prevent project.title, users and their rights from being modify made by managers. I use Y.js & y-socket.io Maybe you have already met the problem and know how to deal with it.