Including modules and classes in rails
module TwitterPost
  include ActionView::Helpers::NumberHelper

  def update
    number_with_delimiter(1234567)
  end
end

NoMethodError: undefined method `number_with_delimiter' for TwitterPost:Module

module TwitterPost
  include ActionView::Helpers::NumberHelper

  def update
    number_with_delimiter(1234567)
  end
end

class Foo
  include TwitterPost
end

foo = Foo.new
foo.update
   => "1,234,567"