docs/bundle.js
function batchedUpdates(fn, a) {
    var previousIsBatchingUpdates = isBatchingUpdates;
    isBatchingUpdates = true;
    try {
      return fn(a);
    } finally {
      isBatchingUpdates = previousIsBatchingUpdates;
      if (!isBatchingUpdates && !isRendering) {
        performWork(Sync, null);
      }
    }
  }
function batchedUpdates(fn, a) {
    var previousIsBatchingUpdates = isBatchingUpdates;
    isBatchingUpdates = true;
    try {
      return fn(a);
    } finally {
      isBatchingUpdates = previousIsBatchingUpdates;
      if (!isBatchingUpdates && !isRendering) {
        performWork(Sync, null);
      }
    }
  }
TODO: Batching should be implemented at the renderer level, not inside the reconciler.