You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: repo_build_started.rb
    path of file: ./repos/open-build-service/src/api/app/models/event
    
    the code of the file until where you have to start completion: module Event
  class 
    
    def clear_caches
      # TODO: We should touch the repository instead of deleting the key
      # to invalidate the cache. However, repository currently does not have
      # an updated_at column so we can not use Rails' cache_key method.
      project_name = payload['project']
      repository_name = payload['repo']
      architecture_name = payload['arch']
      Rails.cache.delete("build_id-#{project_name}-#{repository_name}-#{architecture_name}")
    end
  end