instance method default_serializer

# File activesupport/lib/active_support/cache.rb, line 762
        def default_serializer
          case Cache.format_version
          when 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[:marshal_6_1]
          when 7.0
            Cache::SerializerWithFallback[:marshal_7_0]
          when 7.1
            Cache::SerializerWithFallback[:marshal_7_1]
          else
            raise ArgumentError, "Unrecognized ActiveSupport::Cache.format_version: #{Cache.format_version.inspect}"
          end
        end