toAtprotoJson method
Returns the atproto data model JSON representation of this CID.
Emits {"$link": "<base32 cid>"} as required by the atproto data model
(https://atproto.com/specs/data-model).
Note: atproto record bodies are normally serialized through the CBOR/CAR
path (which builds the $link map directly from the CID string), not via
this method. This method exists for callers that need the atproto link
shape from a CID in pure JSON.
Implementation
Map<String, dynamic> toAtprotoJson() => {_atprotoJsonKey: _format()};