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: 20181112125034_create_doorkeeper_tables.rb
    path of file: ./repos/openproject/db/migrate
    
    the code of the file until where you have to start completion: #-- copyright
# OpenProject is an open source project management software.
# Copyright (C) 2012-2024 the OpenProject GmbH
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License version 3.
#
# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
# Copyright (C) 2006-2013 Jean-Philippe Lang
# Copyright (C) 2010-2013 the ChiliProject Team
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# See COPYRIGHT and LICENSE files for more details.
#++

class CreateDoorkeeperTables < ActiveRecord::Migration[5.1]
  def change
    create_table :oauth_applications do |t|
      t.string  :name,         null: false
      t.string  :uid,          null: false
      t.string  :secret,       null: false
      t.string  :owner_type
      t.integer :owner_id
     
    
  def change
    create_table :oauth_applications do |t|
      t.string  :name,         null: false
      t.string  :uid,          null: false
      t.string  :secret,       null: false
      t.string  :owner_type
      t.integer :owner_id
      t.integer :client_credentials_user_id
      t.text    :redirect_uri, null: false
      t.string  :scopes,       null: false, default: ''
      t.boolean :confidential, null: false, default: true
      t.timestamps             null: false
    end

    # Add owner of an application
    add_foreign_key :oauth_applications, :users, column: :owner_id, on_delete: :nullify

    # Allow to map a user to use for client credentials auth flow
    add_foreign_key :oauth_applications, :users, column: :client_credentials_user_id, on_delete: :nullify

    add_index :oauth_applications, :uid, unique: true
    add_index :oauth_applications, %i[owner_id owner_type]

    create_table :oauth_access_grants do |t|
      t.references :resource_owner,  null: false
      t.references :application,     null: false
      t.string   :token,             null: false
      t.integer  :expires_in,        null: false
      t.text     :redirect_uri,      null: false
      t.datetime :created_at,        null: false
      t.datetime :revoked_at
      t.string   :scopes
    end

    add_index :oauth_access_grants, :token, unique: true
    add_foreign_key(
      :oauth_access_grants,
      :oauth_applications,
      column: :application_id
    )

    create_table :oauth_access_tokens do |t|
      t.references :resource_owner, index: true
      t.references :application

      # If you use a custom token generator you may need to change this column
      # from string to text, so that it accepts tokens larger than 255
      # characters. More info on custom token generators in:
      # https://github.com/doorkeeper-gem/doorkeeper/tree/v3.0.0.rc1#custom-access-token-generator
      #
      # t.text     :token,             null: false
      t.string   :token, null: false

      t.string   :refresh_token
      t.integer  :expires_in
      t.datetime :revoked_at
      t.datetime :created_at, null: false
      t.string   :scopes

      # If there is a previous_refresh_token column,
      # refresh tokens will be revoked after a related access token is used.
      # If there is no previous_refresh_token column,
      # previous tokens are revoked as soon as a new access token is created.
      # Comment out this line if you'd rather have refresh tokens
      # instantly revoked.
      t.string   :previous_refresh_token, null: false, default: ""
    end

    add_index :oauth_access_tokens, :token, unique: true
    add_index :oauth_access_tokens, :refresh_token, unique: true
    add_foreign_key(
      :oauth_access_tokens,
      :oauth_applications,
      column: :application_id
    )

    # Add PKCE challenges column
    add_column :oauth_access_grants, :code_challenge, :string, null: true
    add_column :oauth_access_grants, :code_challenge_method, :string, null: true
  end