/**
  * same as {@link #getWordSet(ResourceLoader, String, boolean)}, except the input is in snowball
  * format.
  */
 protected final CharArraySet getSnowballWordSet(
     ResourceLoader loader, String wordFiles, boolean ignoreCase) throws IOException {
   List<String> files = splitFileNames(wordFiles);
   CharArraySet words = null;
   if (files.size() > 0) {
     // default stopwords list has 35 or so words, but maybe don't make it that
     // big to start
     words = new CharArraySet(files.size() * 10, ignoreCase);
     for (String file : files) {
       InputStream stream = null;
       Reader reader = null;
       try {
         stream = loader.openResource(file.trim());
         CharsetDecoder decoder =
             StandardCharsets.UTF_8
                 .newDecoder()
                 .onMalformedInput(CodingErrorAction.REPORT)
                 .onUnmappableCharacter(CodingErrorAction.REPORT);
         reader = new InputStreamReader(stream, decoder);
         WordlistLoader.getSnowballWordSet(reader, words);
       } finally {
         IOUtils.closeWhileHandlingException(reader, stream);
       }
     }
   }
   return words;
 }