# File lib/devise/models/validatable.rb, line 20
      def self.included(base)
        base.extend ClassMethods
        assert_validations_api!(base)

        base.class_eval do
          validates_presence_of   :email, :if => :email_required?
          validates_uniqueness_of :email, :case_sensitive => (case_insensitive_keys != false), :allow_blank => true, :if => :email_changed?
          validates_format_of     :email, :with  => email_regexp, :allow_blank => true, :if => :email_changed?

          validates_presence_of     :password, :if => :password_required?
          validates_confirmation_of :password, :if => :password_required?
          validates_length_of       :password, :within => password_length, :allow_blank => true
        end
      end