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: tag.rb
    path of file: ./repos/qpixel/app/models
    
    the code of the file until where you have to start completion: class Tag < ApplicationRecord
  include Communit
    
  def parent_chain
    Enumerator.new do |enum|
      parent_group = group
      until parent_group.nil?
        enum.yield parent_group
        parent_group = parent_group.group
      end
    end