'When L{deprecated} is used on a class, instantiations raise a
L{DeprecationWarning} and class\'s docstring is updated to inform the
version in which it was deprecated. C{deprecatedVersion} attribute is
also set to inform the deprecation version.'

def test_class(self):

    DeprecatedClass()
    self.assertDocstring(DeprecatedClass, ['Class    which    is    entirely    deprecated    without    having    a    replacement.', 'Deprecated    in    Twisted    1.2.3.'])
    DeprecatedClass.deprecatedVersion = Version('Twisted', 1, 2, 3)
    message = 'twisted.python.test.test_deprecate.DeprecatedClass    was    deprecated    in    Twisted    1.2.3'
    warnings = self.flushWarnings([self.test_class])
    self.assertEqual(1, len(warnings))
    self.assertEqual(DeprecationWarning, warnings[0]['category'])
    self.assertEqual(message, warnings[0]['message'])
