def put_all(indexables)
      documents = indexables.map do |indexable|
        generate_document(indexable)
      end
      documents.reject!(&:empty?)

      publish_all(documents) unless documents.empty?
    end
def put_all(indexables)
      documents = indexables.map do |indexable|
        generate_document(indexable)
      end
      documents.reject!(&:empty?)

      publish_all(documents) unless documents.empty?
    end
Sends the specified documents to the remote backend
 using bulk upload (if supported by the backend)
 @param [Indexable] an Indexable object