class ActionView::LookupContext

def locale=(value)

acting as proxy, which we need to skip.
to original_config, it means that it's has a copy of the original I18n configuration and it's
Overload locale= to also set the I18n.locale. If the current I18n.config object responds 
def locale=(value)
  if value
    config = I18n.config.respond_to?(:original_config) ? I18n.config.original_config : I18n.config
    config.locale = value
  end
  super(@skip_default_locale ? I18n.locale : default_locale)
end