Tries to drop all databases provided in config passed to ``.init()`` method.
        Normally should be used only for testing purposes.

async def _drop_databases(cls) -> None:
        """
        Tries to drop all databases provided in config passed to ``.init()`` method.
        Normally should be used only for testing purposes.
        """
        if not cls._inited:
            raise ConfigurationError("You have to call .init() first before deleting schemas")
        for connection in cls._connections.values():
            await connection.close()
            await connection.db_delete()
        cls._connections = {}
        await cls._reset_apps()