code: protected final int applyAllCaseFoldWithMap(int mapSize, int[][]map, boolean essTsettFlag, int flag,
                                            ApplyAllCaseFoldFunction fun, Object arg) {
  
          asciiApplyAllCaseFold(flag, fun, arg);
          int[]code = new int[]{0};
  
          for (int i=0; i<mapSize; i++) {
              code[0] = map[i][1];
  
              fun.apply(map[i][0], code, 1, arg);
  
              code[0] = map[i][0];
              fun.apply(map[i][1], code, 1, arg);
          }
  
          if (essTsettFlag) ssApplyAllCaseFold(flag, fun, arg);
          return 0;
      }
docs: onigenc_apply_all_case_fold_with_map