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: digital_object_component.rb
    path of file: ./repos/archivesspace/backend/app/model
    
    the code of the file until where you have to start completion: require_relative 'ancestor_listing'

class DigitalObjectComponent < Sequel::Model(:digital_object_component)
  include ASModel
  corresponds_to JSONModel(:digital_object_component)

  include Subjects
  include Extents
  include LangMaterials
  include Dates
  include ExternalDocuments
  include Agents
  include TreeNodes
  include AutoGenerator
  include Notes
  include RightsStatements
  include ExternalIDs
  include FileVersions
  includ
    
  def self.produce_display_string(json)
    display_string = json['title'] || json['label'] || ""

    date_label = json.has_key?('dates') && json['dates'].length > 0 ?
                  json['dates'].map do |date|
                    if date['expression']
                      date['date_type'] == 'bulk' ? "#{I18n.t("date_type_bulk.bulk")}: #{date['expression']}" : date['expression']
                    elsif date['begin'] and date['end']
                      date['date_type'] == 'bulk' ? "#{I18n.t("date_type_bulk.bulk")}: #{date['begin']} - #{date['end']}" : "#{date['begin']} - #{date['end']}"
                    else
                      date['date_type'] == 'bulk' ? "#{I18n.t("date_type_bulk.bulk")}: #{date['begin']}" : date['begin']
                    end
                  end.join(', ') : false

    display_string += ", " if json['title'] && date_label
    display_string += date_label if date_label

    display_string
  end