class ActionView::I18nProxy

:nodoc:
it will trigger the lookup_context and consequently expire the cache.
This is a class to fix I18n global state. Whenever you provide I18n.locale during a request,

def initialize(original_config, lookup_context) 

def initialize(original_config, lookup_context)
  original_config = original_config.original_config if original_config.respond_to?(:original_config)
  @original_config, @lookup_context = original_config, lookup_context
end

def locale 

def locale
  @original_config.locale
end

def locale=(value) 

def locale=(value)
  @lookup_context.locale = value
end