class ActiveModel::Serializer::CollectionSerializer

def serializable_hash(adapter_options, options, adapter_instance)
  options[:include_directive] ||= ActiveModel::Serializer.include_directive_from_options(adapter_options)
  options[:cached_attributes] ||= ActiveModel::Serializer.cache_read_multi(self, adapter_instance, options[:include_directive])
  serializers.map do |serializer|
    serializer.serializable_hash(adapter_options, options, adapter_instance)
  end
end