Next-Range:

[1] Platform API Reference | Heroku Dev Center ( (2014-10-08 12:29:52 +09:00 版)) <https://devcenter.heroku.com/articles/platform-api-reference#ranges>

[2] Platform API Reference | Heroku Dev Center (2015-03-06 08:14:31 +09:00 版) <https://devcenter.heroku.com/articles/platform-api-reference#ranges>

If a list response has been truncated you will receive a 206 Partial Content status and the Next-Range header set. To retrieve the next range, repeat the request with the Range header set to the value of the previous request’s Next-Range header.
The number of values returned in a range can be controlled using a max key in the Range header. For example, to get only the first 10 values, set this header: Range: id ..; max=10;. max can also be passed when iterating over Next-Range. The default page size is 200 and maximum page size is 1000.