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: sku.rb
    path of file: ./repos/workarea/core/app/models/workarea/inventory
    
    the code of the file until where you have to start completion: module Workarea
  module Inventory
    class Sku
      class InvalidPolicy < RuntimeError; end

    
      def policy_class
        "Workarea::Inventory::Policies::#{policy.camelize}".constantize
      rescue NameError
        raise(
          InvalidPolicy,
          "Workarea::Inventory::Policies::#{policy.camelize} must be a policy class"
        )
      end