class ActiveModel::Serializer

def attribute(attr, options={})
  self._attributes = _attributes.merge(attr.is_a?(Hash) ? attr : {attr => options[:key] || attr.to_s.gsub(/\?$/, '').to_sym})
  attr = attr.keys[0] if attr.is_a? Hash
  unless method_defined?(attr)
    define_method attr do
      object.read_attribute_for_serialization(attr.to_sym)
    end
  end
  define_include_method attr
  # protect inheritance chains and open classes
  # if a serializer inherits from another OR
  #  attributes are added later in a classes lifecycle
  # poison the cache
  define_method :_fast_attributes do
    raise NameError
  end
end