function baseSortBy(array, comparer) {
	      var length = array.length;

	      array.sort(comparer);
	      while (length--) {
	        array[length] = array[length].value;
	      }
	      return array;
	    }
The base implementation of `_.sortBy` which uses `comparer` to define
the sort order of `array` and replaces criteria objects with their
corresponding values.

@private
@param {Array} array The array to sort.
@param {Function} comparer The function to define sort order.
@returns {Array} Returns `array`.