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: migration.rb
    path of file: ./repos/gitlabhq/lib/container_registry
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module ContainerRegistry
  module Migration
    # Some container repositories do not have a plan associated with them, they will be imported with
    # the free tiers
    FREE_TIERS = ['free', 'early_adopter', nil].freeze
    PREMIUM_TIERS = %w[premium bronze silver premium_trial].freeze
    ULTIMATE_TIERS = %w[ultimate gold ultimate_tr
    
    def self.capacity
      # Increasing capacity numbers will increase the n+1 API calls we can have
      # in ContainerRegistry::Migration::GuardWorker#external_migration_in_progress?
      #
      # TODO: See https://gitlab.com/gitlab-org/container-registry/-/issues/582
      #
      return 40 if Feature.enabled?(:container_registry_migration_phase2_capacity_40)
      return 25 if Feature.enabled?(:container_registry_migration_phase2_capacity_25)
      return 10 if Feature.enabled?(:container_registry_migration_phase2_capacity_10)
      return 5 if Feature.enabled?(:container_registry_migration_phase2_capacity_5)
      return 2 if Feature.enabled?(:container_registry_migration_phase2_capacity_2)
      return 1 if Feature.enabled?(:container_registry_migration_phase2_capacity_1)

      0
    end