code: function baseSortedIndex(array, value, retHighest) {
        var low = 0,
            high = array == null ? low : array.length;
  
        if (typeof value == 'number' && value === value && high <= HALF_MAX_ARRAY_LENGTH) {
          while (low < high) {
            var mid = (low + high) >>> 1,
                computed = array[mid];
  
            if (computed !== null && !isSymbol(computed) &&
                (retHighest ? (computed <= value) : (computed < value))) {
              low = mid + 1;
            } else {
              high = mid;
            }
          }
          return high;
        }
        return baseSortedIndexBy(array, value, identity, retHighest);
      }
docs: The base implementation of `_.sortedIndex` and `_.sortedLastIndex` which
  performs a binary search of `array` to determine the index at which `value`
  should be inserted into `array` in order to maintain its sort order.
  
  @private
  @param {Array} array The sorted array to inspect.
  @param {*} value The value to evaluate.
  @param {boolean} [retHighest] Specify returning the highest qualified index.
  @returns {number} Returns the index at which `value` should be inserted
  into `array`.