code: public static void registerClass(String ID, Class<? extends Transliterator> transClass, String displayName) {
          registry.put(ID, transClass, true);
          if (displayName != null) {
              displayNameCache.put(new CaseInsensitiveString(ID), displayName);
          }
      }
docs: Registers a subclass of <code>Transliterator</code> with the
  system.  This subclass must have a public constructor taking no
  arguments.  When that constructor is called, the resulting
  object must return the <code>ID</code> passed to this method if
  its <code>getID()</code> method is called.
  
  @param ID the result of <code>getID()</code> for this
  transliterator
  @param transClass a subclass of <code>Transliterator</code>
  @see #unregister