@Test
    public void testValidCustomTz() throws GuacamoleException {
        for (String tzStr : TZ_CUSTOM_VALID) {
            String tzId = WHERE_IN_WORLD.parseValue(tzStr).getID();
            assertNotNull(tzId);
        }
    }
Tests several custom offsets from GMT to make sure that they are returned
as valid TimeZone objects.

@throws GuacamoleException 
    If the test unexpectedly fails because a custom offset throws an
    exception as an invalid TimeZone.
guacamole-ext/src/test/java/org/apache/guacamole/properties/TimeZoneGuacamolePropertyTest.java