unregister method
Implementation
@override
void unregister(DepAccess access) {
if (!_registered) {
throw ScopeError(
'Dep._unregister() is called when it\'s not really registered yet — '
'this is definitely an error in the library, '
'please contact an owner, if you see this message.',
);
}
final value = _value?.value;
_value = null;
access.observer?.onValueCleared(access.dep, value);
_registered = false;
}