A JSON object whose key order survives encoding.

Elixir maps of more than 32 keys iterate in hash order, so a window of 40 passages encoded from a map reaches the model shuffled, and the model reads neighbours. Wherever order carries meaning (a screening window, a concern's gathered passages) Cite sends one of these instead.

A provider meets one as a value in a request's "state". It implements Access, so it reads like a map (object["U014"]), and Jason.Encoder, so it encodes as a JSON object with its keys in order. A provider that sends the request as JSON needs nothing else. pairs holds the keys and values in order, for a provider that converts the request to another shape.