code: public static Set<IndexFlavor> of(final IndexFlavor first, final IndexFlavor... rest) {
          final Set<IndexFlavor> set = new HashSet<>();
          set.add(first);
          set.addAll(Arrays.asList(rest));
          return set;
      }
docs: Returns a set containing the given index flavours
  @param first The first index flavour to add
  @param rest The remaining index flavours to add
  @return A set containing the given index flavours