register static method
Implementation
static void register(DataSource instance) {
if (instance is DataRepository) {
DataRepository.register(instance);
} else {
var id = instance.id;
var prev = instances[id];
if (identical(prev, instance)) return;
if (prev != instance) {
instances[id] = instance;
onRegister.add(instance);
DataHandler.onRegister.add(instance);
}
}
}