Motivation

Docs mention:

// Only remap the environment variables, not the JSON config
let keyMappedEnvProvider = KeyMappingProvider(upstream: envProvider) { key in
    key.prepending(["myapp", "prod"])
}

but prepending(_:)/appending(_:) were internal.

Modifications

Switched internal to public.

Result

KeyMappingProvider is easier to use :-)

Test Plan

n/a