function baseNth(array, n) {
      var length = array.length;
      if (!length) {
        return;
      }
      n += n < 0 ? length : 0;
      return isIndex(n, length) ? array[n] : undefined;
    }
The base implementation of `_.nth` which doesn't coerce arguments.

@private
@param {Array} array The array to query.
@param {number} n The index of the element to return.
@returns {*} Returns the nth element of `array`.