// Verify that empty optional is returned
        assertNotNull(result);
        assertFalse(result.isPresent());
    }

    // Test getRequestedTimeZone() method
    @Test
    public void test_getRequestedTimeZone() {
        // Execute
        TimeZone result = provider.getRequestedTimeZone(requestManager);

        // Verify that the central time zone is returned
        assertNotNull(result);