@Test
    public void testValidGMT() throws GuacamoleException {
        for (String tzStr : TZ_GMT_VALID) {
            String tzId = WHERE_IN_WORLD.parseValue(tzStr).getID();
            assertNotNull(tzId);
        }
    }
Tests a list of strings that should be valid representations of the GMT
time zone, throwing an exception if an invalid String is found.

@throws GuacamoleException 
    If the test value incorrectly fails to parse as a valid GMT string.
guacamole-ext/src/test/java/org/apache/guacamole/properties/TimeZoneGuacamolePropertyTest.java