I dive into the protocol directory.

I found that the protocol sub-package only depends on core/utility.go and core.Context.

I think you can create a util sub-package and put core/utility.go and core.Context in it.

What do you think of it? Or I can do it myself, and make a PR.

Append...

The protocol sub package also depends on config.go and logger.go. It may be not easy to export the protocol package.