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: issue.rb
    path of file: ./repos/gitlabhq/app/models
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require 'carrierwave/orm/activerecord'

class Issue < ApplicationRecord
  include AtomicInternalId
  include IidRoutes
  include Issuable
  include Noteable
  include Referable
  include Spammable
  include FasterCacheKeys
  include RelativePositioning
  include TimeTrackable
  include ThrottledTouch
  include LabelEventable
  include MilestoneEventable
  include Wher
    
  def self.simple_sorts
    super.merge(
      {
        'closest_future_date' => -> { order_closest_future_date },
        'closest_future_date_asc' => -> { order_closest_future_date },
        'due_date' => -> { order_due_date_asc.with_order_id_desc },
        'due_date_asc' => -> { order_due_date_asc.with_order_id_desc },
        'due_date_desc' => -> { order_due_date_desc.with_order_id_desc },
        'relative_position' => -> { order_by_relative_position },
        'relative_position_asc' => -> { order_by_relative_position }
      }
    )
  end