anchor.diff:  
   ## Resources
   
  -There're already few blog posts about building an event sourced applications with [rails_event_store](https://github.com/RailsEventStore/rails_event_store) and `aggregate_root` gems:
  +There're already a few blog posts about building event sourced applications with [rails_event_store](https://github.com/RailsEventStore/rails_event_store) and `aggregate_root` gems:
   
   - [Why use Event Sourcing](https://blog.arkency.com/2015/03/why-use-event-sourcing/)
   - [The Event Store for Rails developers](https://blog.arkency.com/2015/04/the-event-store-for-rails-developers/)
  
positive.code: end
  ```
  
  The convention is to use `apply_` plus an underscored event class name for event handler methods. I.e. when you apply `OrderExpired` event, the `apply_order_expired` method is called.
  
  #### Alternative syntax for event handler methods.
  
  You can use class method `on(event_klass, &method)` for defining those methods alternatively. This is useful because you can more easily grep/find where events are used in your codebase.
  
  ```ruby
  class Order
  
negative.code: end
  ```
  
  Remember that this is only a default event store used by the `AggregateRoot` module to initialize `AggregateRoot::Repository` when no event store is given in the repository's constructor as an argument.
  
  ## Usage
  
  To create a new aggregate domain object, include the `AggregateRoot` module.
  
  ```ruby
  class Order
  