Writing unit test cases for jekyll plugins need to access the context.registers.

Hello ,
I am writing unit test cases for my jekyll plugins , where I need the site variable and context.registers .
I was able to get the site variable using the process used by jekyll-algolia plugin [link to jekyll-algolia spec_helper.rb](https://github.com/algolia/jekyll-algolia/blob/develop/spec/spec_helper.rb).
Is there a way i can also access the `@context.register` using the way got access to site variable?

Start with the linked jekyll-algolia spec_helper.rb and compare how it obtains the site variable with the Jekyll context.registers access described in the issue. Check whether the existing test setup can expose the registers, and document or demonstrate a reproducible approach if one exists.

Written by the indexing model from the issue text.