How pass modified context for child fields

[ahrushetskyi]

Quote from https://graphql-ruby.org/queries/interpreter.html#implementation-notes :

Instead of creating a GraphQL::Query::Context::FieldResolutionContext for every field in the response, the interpreter uses long-lived, mutable objects for execution bookkeeping. This is more complicated to manage, since the changes to those objects can be hard to predict, but it’s worth it for the performance gain. When needed, those bookkeeping objects can be “forked”, so that two parts of an operation can be resolved independently.

How it actually can be forked or modified for child fields?

I was not able to find any documentation for #merge_scoped!, looks like it does exactly that.