code: function (start) {
      var index = start || 0,
        length = this.string.length,
        region = length;
  
      while (index < length - 1 && region === length) {
        if (this.hasVowelAtIndex(index) && !this.hasVowelAtIndex(index + 1)) {
          region = index + 2;
        }
        index++;
      }
  
      return region;
    }
docs: Marks a region after the first non-vowel following a vowel, or the
  null region at the end of the word if there is no such non-vowel.
  
  @param {Object} token Token to stem.
  @param {Number} start Start index (defaults to 0).
  @param {Number}       Region start index.