anchor.diff:    config.to_prepare do
       Rails.configuration.event_store = RailsEventStore::Client.new(
         mapper: RubyEventStore::Mappers::Default.new(
  -        serializer: JSON
  +        serializer: Marshal
         )
       )
     end
  
positive.code: OrderPlaced = Class.new(MyEvent)
  ```
  
  That shields you from data keys being transformed from symbols into strings. It doesn't do anything with data values though so beware.
  
  ```ruby
  event_store.publish(OrderPlaced.new(event_id: 'e34fc19a-a92f-4c21-8932-a10f6fb2602b', data: { foo: :bar }))
  
negative.code: # => "bar"
  ```
  
    <p class="text-base inline-block">
      Another way to achive that could be define your own <a href="https://railseventstore.org/docs/mapping_serialization/#custom-mapper">custom mapper and transformation</a>
    </p>
  </div>
  
  
  
  
  
  
  ### Available mappers
  
  