// Package httpapi contains code for calling HTTP APIs.
//
// We model HTTP APIs as follows:
//
// 1. |Endpoint| is an API endpoint (e.g., https://api.ooni.io);
//
// 2. |Descriptor| describes the specific API you want to use (e.g.,
// GET /api/v1/test-list/urls with JSON response body).
//
// Generally, you use |Call| to call the API identified by a |Descriptor|
// on the specified |Endpoint|. However, there are cases where you
// need more complex calling patterns. For example, with |SequenceCaller|
// you can invoke the same API |Descriptor| with multiple equivalent
// API |Endpoint|s until one of them succeeds or all fail.
package httpapi