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: callbacks.rb
    path of file: ./repos/solidus/backend/lib/spree/backend
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Spree
  module Backend
    module Callbacks
      extend Ac
    
      def invoke_callbacks(action, callback_type)
        callbacks = self.class.callbacks || {}
        return if callbacks[action].nil?
        case callback_type.to_sym
        when :before then callbacks[action].before_methods.each { |method| send method }
        when :after  then callbacks[action].after_methods.each  { |method| send method }
        when :fails  then callbacks[action].fails_methods.each  { |method| send method }
        end