Trying to use a sequel model without a table

sequel_model_without_a_table.rb

class Foo < Sequel::Model
  plugin :timestamps, :create => :created_on, :update => :updated_on
  plugin :validation_helpers

  many_to_one :user

  def initialize(params={}) ... end

  def before_save ... end

  def after_create ... end

  def validate ... end
end

class Bar1 < Foo
  self.set_dataset :bar1
  ...
end
class Bar2 < Foo
  self.set_dataset :bar2
  ...
end