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: 20131209091702_create_post_revisions.rb
    path of file: ./repos/discourse/db/migrate
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

class CreatePostRevisions < ActiveRecord::Migration[4.2]
  def up
    create_table :post_revisio
    
  def up
    create_table :post_revisions do |t|
      t.belongs_to :user
      t.belongs_to :post
      t.text :modifications
      t.integer :number
      t.timestamps null: false
    end

    execute "INSERT INTO post_revisions (user_id, post_id, modifications, number, created_at, updated_at)
             SELECT user_id, versioned_id, modifications, number, created_at, updated_at
             FROM   versions
             WHERE  versioned_type = 'Post'"

    change_table :post_revisions do |t|
      t.index :post_id
      t.index %i[post_id number]
    end
  end