how to use a plain old ruby object PORO and an active_model_serializers Serializer (0.10.x)

gistfile1.rb

ruby object: 

class SearchResult
  extend ActiveModel::Naming
  include ActiveModel::Serialization
  attr_accessor :stories, :users, :friends

  def id
    hash 
  end

  def initialize(search:)
    @stories = search.stories
    @users = search.users
    @friends = search.friends
  end

  def attributes
    { stories: stories,
      users: users,
      friends: friends
    }
  end
end

Serializer: 
class SearchResultSerializer < ActiveModel::Serializer
  attributes :stories, :users, :friends
end