Trying to dynamically create around_ callbacks in ActiveRecord

Piddle.rb

# A module for creating around callbacks in a model
module Piddle
  module TimelineFor
    def self.included(klass)
      klass.send(:extend, ClassMethods)
    end

    module ClassMethods
      def timeline_for(event, opts={})
        method_name = :"timeline_for_#{event.to_s}"
        define_method(method_name) do |&block|
          Rails.logger.debug method_name.to_s
          yield block
          Rails.logger.debug "After yield in #{method_name.to_s}"
        end

        send(:around_update, method_name)
      end
    end
  end
end

User.rb

class User < ActiveRecord::Base
  around_update :test_update

  def test_update
    Rails.logger.debug "test_update"
    yield
    Rails.logger.debug "Finished test_update"
  end
end

u=User.last
u.name = 'something'
u.save

######### output (as expected):
# test_update
# Finished test_update

User2.rb

# second version of the User model using Piddle to create the callback
require 'piddle/piddle'

class User2 < ActiveRecord::Base
  include Piddle::TimelineFor

  timeline_for :update
end

u=User.last
u.name = 'gfgfhfhfgh'
u.save

########### output
timeline_for_update
LocalJumpError: no block given (yield)
from /vagrant/lib/piddle/piddle.rb:13:in `block in timeline_for'