async def METHOD_NAME(self, client, alias_name, new_index, old_index):
    await self._create_index(client, new_index)
    alias = SearchAlias(name=alias_name, indexes=[new_index])
    result = await client.create_or_update_alias(alias)
    assert result.name == alias_name
    assert result.indexes[0] != old_index
    assert result.indexes[0] == new_index