func (s *scratch) add(c byte) {
	if s.fill+1 >= cap(s.data) {
		s.grow()
	}

	s.data[s.fill] = c
	s.fill++
}

// append encoded rune to scratch buffer
func (s *scratch) addRune(r rune) int {
	if s.fill+utf8.UTFMax >= cap(s.data) {
		s.grow()
	}

	n := utf8.EncodeRune(s.data[s.fill:], r)
	s.fill += n
	return n

    }

    @Test
    public void test_addRole() throws Exception {
        indexQueryItems();

        PopularWordsResponse response = suggester.popularWords().setSize(10).addRole(SuggestConstants.DEFAULT_ROLE).execute().getResponse();

        assertNotNull(response);
        assertTrue(response.getTotal() > 0);
    }

    @Test
    public void test_addField() throws Exception {

	c = d.next()
	if !utf16.IsSurrogate(r) || c != '\\' {
		d.scratch.addRune(r)
		goto scan
	}
	if c = d.next(); c != 'u' {
		d.scratch.addRune(r)
		goto scan_esc
	}

	r2 := d.u4()
	if r2 < 0 {
		return "", d.mkError(ErrSyntax, "in unicode escape sequence")
	}

	// write surrogate pair
	d.scratch.addRune(utf16.DecodeRune(r, r2))
	c = d.next()
	goto scan
}

 * SuggestRequest suggestRequest = new SuggestRequest();
 * suggestRequest.setIndex("my_index");
 * suggestRequest.setQuery("example query");
 * suggestRequest.setSize(5);
 * suggestRequest.addTag("tag1");
 * suggestRequest.addRole("role1");
 * suggestRequest.addField("field1");
 * suggestRequest.addKind("kind1");
 * suggestRequest.addLang("en");
 * suggestRequest.setSuggestDetail(true);
 * suggestRequest.setReadingConverter(new MyReadingConverter());

                stream(baseTags).of(stream -> stream.forEach(tag -> popularWordsRequestBuilder.addTag(tag)));
                stream(baseRoles).of(stream -> stream.forEach(role -> popularWordsRequestBuilder.addRole(role)));
                stream(baseFields).of(stream -> stream.forEach(field -> popularWordsRequestBuilder.addField(field)));

     */
    public void addTag(final String tag) {
        tags.add(tag);
    }

    /**
     * Adds a role to filter by.
     * @param role The role.
     */
    public void addRole(final String role) {
        roles.add(role);
    }

    /**
     * Adds a field to filter by.
     * @param field The field name.
     */
    public void addField(final String field) {

        SuggestItem[] items = getItemSet1();
        suggester.indexer().index(items);
        suggester.refresh();

        SuggestResponse response = suggester.suggest().setQuery("kensaku").addRole("role1").setSuggestDetail(true).execute().getResponse();
        assertEquals(1, response.getNum());
        assertEquals("検索 エンジン", response.getWords().get(0));

        suggester.indexer().delete(items[0].getId());

    assertTransformModifiable(list);
  }

  private static void assertTransformModifiable(List<String> list) {
    try {
      list.add("5");
      fail("transformed list is addable");
    } catch (UnsupportedOperationException expected) {
    }
    list.remove(0);
    assertEquals(asList("2", "3", "4"), list);
    list.remove("3");
    assertEquals(asList("2", "4"), list);
    try {

            stream(parameter.getSuggestFields()).of(stream -> stream.forEach(builder::addField));
            roleQueryHelper.build(SearchRequestType.SUGGEST).stream().forEach(builder::addRole);
            builder.setSize(parameter.getNum());
            stream(langs).of(stream -> stream.forEach(builder::addLang));

            stream(parameter.getTags()).of(stream -> stream.forEach(builder::addTag));

a1×b0 + 19×(a2×b4 + a3×b3 + a4×b2) r1 := mul(a0, b1) r1 = addMul(r1, a1, b0) r1 = addMul19(r1, a2, b4) r1 = addMul19(r1, a3, b3) r1 = addMul19(r1, a4, b2) // r2 = a0×b2 + a1×b1 + a2×b0 + 19×(a3×b4 + a4×b3) r2 := mul(a0, b2) r2 = addMul(r2, a1, b1) r2 = addMul(r2, a2, b0) r2 = addMul19(r2, a3, b4) r2 = addMul19(r2, a4, b3) // r3 = a0×b3 + a1×b2 + a2×b1 + a3×b0 + 19×a4×b4 r3 := mul(a0, b3) r3 = addMul(r3, a1, b2) r3 = addMul(r3, a2, b1) r3 = addMul(r3, a3, b0) r3 = addMul19(r3, a4, b4) // r4 = a0×b4 +...