code: protected static Set<String> newHashSet(String... strings) {
          final Set<String> set = new HashSet<>(strings.length);
          Collections.addAll(set, strings);
          return set;
      }
docs: <p>
  Utility method to help in the creation of the extensions set. This
  constructs a new Set that can be used in a final static declaration.</p>
  <p>
  This implementation was copied from
  http://stackoverflow.com/questions/2041778/prepare-java-hashset-values-by-construction</p>
  
  @param strings a list of strings to add to the set.
  @return a Set of strings.