base.rb

module ActiveRecord 
    class Base
    extend ActiveModel::Naming
    extend ActiveSupport::Benchmarkable
...
...
    extend Translation
    extend DynamicMatchers
    extend Explain
    extend Enum
    extend Delegation::DelegateCache
    include Core
    include Persistence
    include NoTouching
    include ActiveModel::Conversion
    include Integration
    include Validations
...
...
    include AttributeMethods
    include Callbacks
    include Timestamp
    include Associations
    include ActiveModel::SecurePassword
    include Serialization
    include Store
    include Core
    end
  ActiveSupport.run_load_hooks(:active_record, Base)
end