pass thru chunker of the dataframe/series

        returns
        -------
        ('NA', 'NA', 'NA', dataframe/series)

def to_chunks(self, df, **kwargs):
        """
        pass thru chunker of the dataframe/series

        returns
        -------
        ('NA', 'NA', 'NA', dataframe/series)
        """
        if len(df) > 0:
            yield b'NA', b'NA', b'NA', df