@Test
public void shouldReadStringList() {

    List<String> list = new ArrayList<>();
    observer.onStringListValue("prop", "foo,bar", l -> {
        list.clear();
        list.addAll(l);
    });
    assertThat(list).containsExactly("foo", "bar");
    writeConfigLine("prop=a,  b ,c");
    assertThat(list).containsExactly("a", "b", "c");
}