code: static void register() {
  
          HashMap<String, Set<String>> seen = new HashMap<String, Set<String>>(); // old code used set, but was dependent on order
  
          for (Enumeration<String> s = Transliterator.getAvailableSources(); s.hasMoreElements(); ) {
              String source = s.nextElement();
  
              // Ignore the "Any" source
              if (source.equalsIgnoreCase(ANY)) continue;
  
              for (Enumeration<String> t = Transliterator.getAvailableTargets(source);
                   t.hasMoreElements(); ) {
                  String target = t.nextElement();
  
                  // Get the script code for the target.  If not a script, ignore.
                  int targetScript = scriptNameToCode(target);
                  if (targetScript == UScript.INVALID_CODE) {
                      continue;
                  }
  
                  Set<String> seenVariants = seen.get(target);
                  if (seenVariants == null) {
                      seen.put(target, seenVariants = new HashSet<String>());
                  }
  
                  for (Enumeration<String> v = Transliterator.getAvailableVariants(source, target);
                       v.hasMoreElements(); ) {
                      String variant = v.nextElement();
  
                      // Only process each target/variant pair once
                      if (seenVariants.contains(variant)) {
                          continue;
                      }
                      seenVariants.add(variant);
  
                      String id;
                      id = TransliteratorIDParser.STVtoID(ANY, target, variant);
                      AnyTransliterator trans = new AnyTransliterator(id, target, variant,
                                                                      targetScript);
                      Transliterator.registerInstance(trans);
                      Transliterator.registerSpecialInverse(target, NULL_ID, false);
                  }
              }
          }
      }
docs: Registers standard transliterators with the system.  Called by
  Transliterator during initialization.  Scan all current targets
  and register those that are scripts T as Any-T/V.