class ActiveSupport::Cache::MemCacheStore

def default_serializer
  if Cache.format_version == 6.1
    ActiveSupport.deprecator.warn <<~EOM
      Support for `config.active_support.cache_format_version = 6.1` has been deprecated and will be removed in Rails 7.2.
      Check the Rails upgrade guide at https://guides.rubyonrails.org/upgrading_ruby_on_rails.html#new-activesupport-cache-serialization-format
      for more information on how to upgrade.
    EOM
    Cache::SerializerWithFallback[:passthrough]
  else
    super
  end
end