'The docstring of the deprecated function is appended with information
about the deprecation.'

def test_deprecatedUpdatesDocstring(self):

    def localDummyCallable():
        '\n                                                Do    nothing.\n\n                                                This    is    used    to    test    the    deprecation    decorators.\n                                                '
    version = Version('Twisted', 8, 0, 0)
    dummy = deprecated(version)(localDummyCallable)
    _appendToDocstring(localDummyCallable, _getDeprecationDocstring(version, ''))
    self.assertEqual(localDummyCallable.__doc__, dummy.__doc__)
