Return an array where each entry is an object with this form:

{ username: "beau", sources: ["fitbit", "runkeeper"] }

GET /api/public-data/sources-by-member/?format=api&offset=67500
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Cache-Control: max-age=0, no-cache, no-store, must-revalidate, private
Content-Type: application/json
Expires: Sun, 11 May 2025 12:33:15 GMT
Vary: Accept

{
    "count": 11944,
    "next": null,
    "previous": "https://www.openhumans.org/api/public-data/sources-by-member/?format=api&limit=100&offset=67400",
    "results": []
}