docs: public char[][] makeFeatureArr(List<Element> list, int index) {
          char[][] result = new char[template.length][];
          char[] chars = null;
          int len = 0;
          int i = 0;
          for (; i < template.length; i++) {
              if (template[i].length == 0) {
                  continue;
              }
              chars = new char[template[i].length + 1];
              len = chars.length - 1;
              for (int j = 0; j < len; j++) {
                  chars[j] = getNameIfOutArr(list, index + template[i][j]);
              }
              chars[len] = (char) (FEATURE_BEGIN + i);
              result[i] = chars;
          }
  
          return result;
      }