@Test
    public void nullTzCheck() throws GuacamoleException {
        assertNull(WHERE_IN_WORLD.parseValue(null));
    }
Tests parse of null input values to make sure the resuling parsed value
is also null.

@throws GuacamoleException
    If the test unexpectedly fails parsing a null value instead
    recognizing it as an invalid value.
guacamole-ext/src/test/java/org/apache/guacamole/properties/TimeZoneGuacamolePropertyTest.java