complete abstract method
- FutureOr<
T> ? value
Completes future with the supplied values.
The value must be either a value of type T
or a future of type Future<T>.
If the value is omitted or null, and T is not nullable, the call
to complete throws.
If the value is itself a future, the completer will wait for that future to complete, and complete with the same result, whether it is a success or an error.
Calling complete or completeError must be done at most once.
All listeners on the future are informed about the value.
Implementation
void complete([FutureOr<T>? value]);