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: channel.rb
    path of file: ./repos/zammad/app/models
    
    the code of the file until where you have to start completion: # Copyright (C) 2012-2024 Zammad Foundation, https://zammad-foundation.org/

class Channel < ApplicationModel
  include Channel::Assets
  include Channel::Area::Whatsapp

  belongs_to :group, optional: true

  store :op
    
  def handle_delivery_error!(error, adapter)
    message = "Can't use Channel::Driver::#{adapter.to_classname}: #{error.inspect}"

    if error.respond_to?(:retryable?) && !error.retryable?
      self.status_out = 'ok'
      self.last_log_out = ''
    else
      logger.error message
      logger.error error

      self.status_out = 'error'
      self.last_log_out = error
    end