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: mapping.rb
    path of file: ./repos/zammad/lib/sequencer/unit/import/freshdesk/conversation
    
    the code of the file until where you have to start completion: # Copyright (C) 2012-2024 Zammad Foundation, https://zammad-foundation.org/

class Sequencer::Unit::Import::Freshdesk::Conversation::Mapping < Sequencer::Unit::Base
  include ::Sequencer::Unit::Import::Common::Mapping::Mixin::ProvideMapped

  uses :resource, :id_map

  # Since the imports rely on a fresh Zammad installation, we
  #   can require the default article types and senders to be present.
  def source_map # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
    @source_map ||= {
      0  => ::Ticket::Article::Type.select(:id).find_by(name: 'email')&.id, # 
    
  def process
    provide_mapped do
      {
        from:          resource['from_email'],
        to:            resource['to_emails']&.join(', '),
        cc:            resource['cc_emails']&.join(', '),
        ticket_id:     ticket_id,
        body:          resource['body'],
        content_type:  'text/html',
        internal:      resource['private'].present?,
        message_id:    resource['id'],
        updated_by_id: user_id,
        created_by_id: user_id,
        sender_id:     incoming_map[ resource['incoming'] ],
        type_id:       source_map[ resource['source'] ] || default_type_id,
        created_at:    resource['created_at'],
        updated_at:    resource['updated_at'],
      }
    end
  end