Function forEachAccumulated

docs/external/js/react-dom.development.js:3378–3384

* @param {array} arr an "accumulation" of items which is either an Array or * a single item. Useful when paired with the `accumulate` module. This is a * simple utility that allows us to reason about a collection of items, but * handling the case when there is exactly one item (and we do no

(arr, cb, scope)

   * @param {?} [scope] Scope used as `this` in a callback.
   */
  function forEachAccumulated(arr, cb, scope) {
    if (Array.isArray(arr)) {
      arr.forEach(cb, scope);
    } else if (arr) {
      cb.call(scope, arr);
    }
  }

  /**
   * Internal queue of events that have accumulated their dispatches and are