load_with_autoloading

# File activesupport/lib/active_support/core_ext/marshal.rb, line 5
    def load_with_autoloading(source)
      load_without_autoloading(source)
    rescue ArgumentError, NameError => exc
      if exc.message.match(%undefined class/module (.+)|)
        # try loading the class/module
        $1.constantize
        # if it is a IO we need to go back to read the object
        source.rewind if source.respond_to?(:rewind)
        retry
      else
        raise exc
      end
    end