function createForEach(arrayFunc, eachFunc) {
  return function(collection, iteratee, thisArg) {
    return (typeof iteratee == 'function' && thisArg === undefined && isArray(collection))
      ? arrayFunc(collection, iteratee)
      : eachFunc(collection, bindCallback(iteratee, thisArg, 3));
  };
}
Creates a function for `_.forEach` or `_.forEachRight`.

@private
@param {Function} arrayFunc The function to iterate over an array.
@param {Function} eachFunc The function to iterate over a collection.
@returns {Function} Returns the new each function.