afterInit method
void
afterInit()
Exit the watch function on the first call.
When this method is called during the initial call to the watch function, the watch function is exited immediately. On subsequent calls this method does nothing
NOTE: Don't use this method within a try block unless the try block excludes StopComputeException.
Implementation
void afterInit() {
if (_observer._initialCall) {
throw ValueCell.none();
}
}