'L{twisted.python.constants.ValueConstant} preserves definition
order in C{<=} comparisons.'

def test_orderedValueConstants_le(self):

    self.assertTrue((ValuedLetters.alpha <= ValuedLetters.alpha))
    self.assertTrue((ValuedLetters.alpha <= ValuedLetters.digamma))
    self.assertTrue((ValuedLetters.digamma <= ValuedLetters.zeta))
