def METHOD_NAME(self):
    data = {}
    t = TransactionMetaData('', '', data)
    self.assertEqual(t.user, b'')
    self.assertEqual(t.description, b'')
    self.assertIs(t.extension, data)
    with warnings.catch_warnings():
        warnings.simplefilter("ignore")
        self.assertEqual(t._extension, t.extension)
        self.assertEqual(t.extension_bytes, b'')
        for name in 'extension', '_extension':
            data = {name: name + 'foo'}
            setattr(t, name, data)
            self.assertIs(t.extension, data)
            self.assertIs(t._extension, t.extension)
            extension_bytes = t.extension_bytes
            self.assertEqual(loads(extension_bytes), data)
            empty = {}
            setattr(t, name, empty)
            self.assertIs(t.extension, empty)
            self.assertIs(t._extension, t.extension)
            self.assertEqual(t.extension_bytes, b'')