function arrayReduce(array, iteratee, accumulator, initFromArray) {
    var index = -1,
        length = array.length;

    if (initFromArray && length) {
      accumulator = array[++index];
    }
    while (++index < length) {
      accumulator = iteratee(accumulator, array[index], index, array);
    }
    return accumulator;
  }
A specialized version of `_.reduce` for arrays without support for callback
shorthands or `this` binding.

@private
@param {Array} array The array to iterate over.
@param {Function} iteratee The function invoked per iteration.
@param {*} [accumulator] The initial value.
@param {boolean} [initFromArray=false] Specify using the first element of
 `array` as the initial value.
@returns {*} Returns the accumulated value.