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: execute_policy_worker.rb
    path of file: ./repos/gitlabhq/app/workers/packages/cleanup
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Packages
  module Cleanup
    class ExecutePolicyWorker
      include ApplicationWorker
      include LimitedCapacity::Worker
      include Gitlab::Utils::StrongMemoize

      data_consistency :always
      queue_namespace :package_cleanup
      feature_category :package_registry
      urgency :low
      worker_resource_boundary :unknown
      idempotent!

      COUNTS_KEYS = %i[
        marked_package_files_total_count
        unique_package_id_and_file_name_total_count
      ].freeze

      def perform_work
        return unless next_policy

        log_extra_metadata_on_done(:pr
    
      def next_policy
        strong_memoize(:next_policy) do
          ::Packages::Cleanup::Policy.transaction do
            # the #lock call is specific to this worker
            # rubocop: disable CodeReuse/ActiveRecord
            policy = ::Packages::Cleanup::Policy.runnable
                                                .limit(1)
                                                .lock('FOR UPDATE SKIP LOCKED')
                                                .first
            # rubocop: enable CodeReuse/ActiveRecord

            next nil unless policy

            policy.set_next_run_at
            policy.save!

            policy
          end
        end
      end