static <E extends Enum<E>> int stateTransitionStringLength(final E from, final E to)
    {
        return SIZE_OF_INT + enumName(from).length() + STATE_SEPARATOR.length() + enumName(to).length();
    }
@Test
    void testStateTransitionStringLength()
    {
        final TimeUnit from = TimeUnit.NANOSECONDS;
        final TimeUnit to = TimeUnit.HOURS;
        assertEquals(from.name().length() + STATE_SEPARATOR.length() + to.name().length() + SIZE_OF_INT,
            stateTransitionStringLength(from, to));
    }