@Test
    public void testInvalidTZs() {
        TZ_TEST_INVALID.forEach((tzStr) -> {
            try {
                String tzId = WHERE_IN_WORLD.parseValue(tzStr).getID();
                fail("Invalid TimeZoneGuacamoleProperty should fail to parse with an exception.");
            }
            catch (GuacamoleException e) {
                String msg = e.getMessage();
                assertTrue(msg.contains("does not specify a valid time zone"));
            }
        });
    }
Tests invalid time zones to make sure that they produce the desired
result, which is an exception thrown failing to parse the value.
guacamole-ext/src/test/java/org/apache/guacamole/properties/TimeZoneGuacamolePropertyTest.java