'L{amp.Decimal.toString} raises L{ValueError} if passed an object which
is not an instance of C{decimal.Decimal}.'

def test_nonDecimal(self):

    argument = amp.Decimal()
    self.assertRaises(ValueError, argument.toString, '1.234')
    self.assertRaises(ValueError, argument.toString, 1.234)
    self.assertRaises(ValueError, argument.toString, 1234)
