public void testSupplementaryCharacters() throws IOException {
final String s = _TestUtil.randomUnicodeString(random(), 10);
final int codePointCount = s.codePointCount(0, s.length());
final int minGram = _TestUtil.nextInt(random(), 1, 3);
final int maxGram = _TestUtil.nextInt(random(), minGram, 10);
TokenStream tk = new KeywordTokenizer(new StringReader(s));
tk = new EdgeNGramTokenFilter(TEST_VERSION_CURRENT, tk, minGram, maxGram);
final CharTermAttribute termAtt = tk.addAttribute(CharTermAttribute.class);
final OffsetAttribute offsetAtt = tk.addAttribute(OffsetAttribute.class);
tk.reset();
for (int i = minGram; i <= Math.min(codePointCount, maxGram); ++i) {
assertTrue(tk.incrementToken());
assertEquals(0, offsetAtt.startOffset());
assertEquals(s.length(), offsetAtt.endOffset());
final int end = Character.offsetByCodePoints(s, 0, i);
assertEquals(s.substring(0, end), termAtt.toString());
}
assertFalse(tk.incrementToken());
}