def parts(options = {})
      batches = Enumerator.new do |y|
        options = options.merge(
          bucket: @bucket_name,
          key: @object_key,
          upload_id: @id
        )
        resp = @client.list_parts(options)
        resp.each_page do |page|
          batch = []
          page.data.parts.each do |p|
            batch << MultipartUploadPart.new(
              bucket_name: options[:bucket],
              object_key: options[:key],
              multipart_upload_id: options[:upload_id],
              part_number: p.part_number,
              data: p,
              client: @client
            )
          end
          y.yield(batch)
        end
      end
      MultipartUploadPart::Collection.new(batches)
    end
def parts(options = {})
      batches = Enumerator.new do |y|
        options = options.merge(
          bucket: @bucket_name,
          key: @object_key,
          upload_id: @id
        )
        resp = @client.list_parts(options)
        resp.each_page do |page|
          batch = []
          page.data.parts.each do |p|
            batch << MultipartUploadPart.new(
              bucket_name: options[:bucket],
              object_key: options[:key],
              multipart_upload_id: options[:upload_id],
              part_number: p.part_number,
              data: p,
              client: @client
            )
          end
          y.yield(batch)
        end
      end
      MultipartUploadPart::Collection.new(batches)
    end
@example Request syntax with placeholder values

   parts = multipart_upload.parts({
     request_payer: "requester", # accepts requester
   })
 @param [Hash] options ({})
 @option options [String] :request_payer
   Confirms that the requester knows that she or he will be charged for
   the request. Bucket owners need not specify this parameter in their
   requests. Documentation on downloading objects from requester pays
   buckets can be found at
   http://docs.aws.amazon.com/AmazonS3/latest/dev/ObjectsinRequesterPaysBuckets.html
 @return [MultipartUploadPart::Collection]