@Test
public void shouldMakeSureExactlyOneOfQueryOrUserIds() {

    ValidationUtil.validateRequestGuildMembers(
        RequestGuildMembers.builder().guildId("1234").query("prefix").limit(0).build(),
        Possible.absent()
    );
    ValidationUtil.validateRequestGuildMembers(
        RequestGuildMembers.builder().guildId("1234").addUserId("9876").limit(1).build(),
        Possible.absent()
    );
    assertThrows(IllegalArgumentException.class, () -> ValidationUtil.validateRequestGuildMembers(
        RequestGuildMembers.builder().guildId("1234").query("prefix").addUserId("5678").limit(0).build(),
        Possible.absent()
    ));
    assertThrows(IllegalArgumentException.class, () -> ValidationUtil.validateRequestGuildMembers(
        RequestGuildMembers.builder().guildId("1234").limit(0).build(),
        Possible.absent()
    ));
}