Called by:

• Mobilizon.Federation.ActivityPub.Federator.handle (L63)
• Mobilizon.Federation.ActivityPub.Fetcher.fetch_and_update (L67)
• Mobilizon.Federation.ActivityPub.Fetcher.pass_to_transmogrifier (L91)
• Mobilizon.Federation.ActivityPub.Refresher.handling_element (L204)
• Mobilizon.Federation.ActivityPub.Refresher.handling_element (L229)
• Mobilizon.Federation.ActivityPub.Transmogrifier.get_participant (L1052)