function asap(callback, context) {
  ("production" !== process.env.NODE_ENV ? invariant(
    batchingStrategy.isBatchingUpdates,
    'ReactUpdates.asap: Can\'t enqueue an asap callback in a context where' +
    'updates are not being batched.'
  ) : invariant(batchingStrategy.isBatchingUpdates));
  asapCallbackQueue.enqueue(callback, context);
  asapEnqueued = true;
}
React references `ReactReconcileTransaction` using this property in order
to allow dependency injection.

@internal