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: dirty.rb
    path of file: ./repos/json_api_client/lib/json_api_client/helpers
    
    the code of the file until where you have to start completion: module JsonApiClient
  module Helpers
    module Dirty

      def changed?
        changed_attributes.present?
      end

      def changed
        chang
    
      def method_missing(method, *args, &block)
        if method.to_s =~ /^(.*)_changed\?$/
          has_attribute?($1) ? attribute_changed?($1) : nil
        elsif method.to_s =~ /^(.*)_was$/
          has_attribute?($1) ? attribute_was($1) : nil
        else
          super
        end