### Question:
GroupId implements Comparable<GroupId> { public String asString() { return name + version.map(it -> VERSION_SEPARATOR + it).orElse(""); }  static GroupId of(String name, int version); static GroupId of(String name, Optional<Integer> version); static GroupId ofString(String str); String asString(); @Override int compareTo(GroupId other); static final Comparator<GroupId> COMPARATOR; static final String VERSION_SEPARATOR; static final Pattern VERSION_PATTERN; }### Answer:
@Test public void testStringRepresentation() { assertThat(object.asString()).isEqualTo(string); }