callbacks property Null safety
read / write
A map of possible out-of band callbacks related to the parent operation.
The key is a unique identifier for the APICallback. Each value in the map is a APICallback that describes a request that may be initiated by the API provider and the expected responses. The key value used to identify the callback object is an expression, evaluated at runtime, that identifies a URL to use for the callback operation.
Implementation
Map<String, APICallback?>? callbacks;