@staticmethod
def producer_work(device, cfg, data):
    """ 
        function specify how the producer processes the data.
        
        Args:
            device (str): device for this process.
            cfg (easycore.common.config.CfgNode): config of this process, you can use it to get data from
                `producer_init` function and transfer data to the next `producer_work` and `producer_end`
                function.
            data (Any): data get from input of `__call__` method.
        
        Returns:
            Any: processed data
        """
    return data
