addListenerCallback method
Add void callback.
Implementation
void addListenerCallback(VoidCallback callback) {
assert(callback != null, 'call back must be provided non-null');
onCallbacks.add(callback);
}
Add void callback.
void addListenerCallback(VoidCallback callback) {
assert(callback != null, 'call back must be provided non-null');
onCallbacks.add(callback);
}