code: @Deprecated
      public void add(StandardPlural rangeStart, StandardPlural rangeEnd,
              StandardPlural result) {
          if (isFrozen) {
              throw new UnsupportedOperationException();
          }
          explicit[result.ordinal()] = true;
          if (rangeStart == null) {
              for (StandardPlural rs : StandardPlural.values()) {
                  if (rangeEnd == null) {
                      for (StandardPlural re : StandardPlural.values()) {
                          matrix.setIfNew(rs, re, result);
                      }
                  } else {
                      explicit[rangeEnd.ordinal()] = true;
                      matrix.setIfNew(rs, rangeEnd, result);
                  }
              }
          } else if (rangeEnd == null) {
              explicit[rangeStart.ordinal()] = true;
              for (StandardPlural re : StandardPlural.values()) {
                  matrix.setIfNew(rangeStart, re, result);
              }
          } else {
              explicit[rangeStart.ordinal()] = true;
              explicit[rangeEnd.ordinal()] = true;
              matrix.setIfNew(rangeStart, rangeEnd, result);
          }
      }
docs: Internal method for building. If the start or end are null, it means everything of that type.
  
  @param rangeStart
  plural category for the start of the range
  @param rangeEnd
  plural category for the end of the range
  @param result
  the resulting plural category
  @deprecated This API is ICU internal only.
  @hide draft / provisional / internal are hidden on Android