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: legacy_compatibility_test.rb
    path of file: ./repos/gitlabhq/vendor/gems/attr_encrypted/test
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

# -*- encoding: utf-8 -*-
require_relative 'test_helper'

# Test to ensure that existing representations in database do not break on
# migrating to new versions of this gem. This ensures that future versions of
# this gem will retain backwards compatibility with data generated by earlier
# versions.
class LegacyCompatibilityTest < Minitest::Test
  class LegacyNonmarshall
    
  def create_tables
    ActiveRecord::Schema.define(:version => 1) do
      create_table :legacy_nonmarshalling_pets do |t|
        t.string :name
        t.string :encrypted_nickname
        t.string :encrypted_birthdate
        t.string :salt
      end
      create_table :legacy_marshalling_pets do |t|
        t.string :name
        t.string :encrypted_nickname
        t.string :encrypted_birthdate
        t.string :salt
      end
    end
  end