@Test
public void testRegexWithZeroWidthAssertions() {

    String regex = "^.*(?=\\?)(?!\\?yy)";
    String source = "hello world?xx?yy";
    RegexSelector regexSelector = new RegexSelector(regex);
    String select = regexSelector.select(source);
    Assertions.assertThat(select).isEqualTo("hello world");
    regex = "\\d{3}(?!\\d)";
    source = "123456asdf";
    regexSelector = new RegexSelector(regex);
    select = regexSelector.select(source);
    Assertions.assertThat(select).isEqualTo("456");
}