'If an object which is neither a function nor a method is included in the
C{offendingFunctions} list, C{flushWarnings} raises L{ValueError}.  Such
a call flushes no warnings.'

def test_invalidFilter(self):

    warnings.warn('oh    no')
    self.assertRaises(ValueError, self.flushWarnings, [None])
    self.assertEqual(len(self.flushWarnings()), 1)
