def _skippable_migrations(self):
        special = [
            216,  # Havana
            272,  # NOOP migration due to revert
        ]

        havana_placeholders = range(217, 227)
        icehouse_placeholders = range(235, 244)
        juno_placeholders = range(255, 265)
        kilo_placeholders = range(281, 291)
        liberty_placeholders = range(303, 313)
        mitaka_placeholders = range(320, 330)

        return (special +
                havana_placeholders -
                icehouse_placeholders +
                juno_placeholders +
                kilo_placeholders +
                liberty_placeholders +
                mitaka_placeholders)
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/tests/unit/db/test_migrations.py/NovaMigrationsCheckers._skippable_migrations/operator `+` -> `-`