code: @Override
      public void addSourceTargetSet(UnicodeSet inputFilter, UnicodeSet sourceSet, UnicodeSet targetSet) {
          // intersect myFilter with the input filter
          UnicodeSet myFilter = getFilterAsUnicodeSet(inputFilter);
          sourceSet.addAll(myFilter);
          // do nothing with the target
      }
docs: /* (non-Javadoc)
  @see android.icu.text.Transliterator#addSourceTargetSet(boolean, android.icu.text.UnicodeSet, android.icu.text.UnicodeSet)