def METHOD_NAME():
    """Retrieve radolan cdc gridded data by DWD."""
    log.info("Acquiring RADOLAN_CDC data")
    radolan = DwdRadarValues(
        parameter=DwdRadarParameter.RADOLAN_CDC,
        resolution=DwdRadarResolution.DAILY,
        period=DwdRadarPeriod.HISTORICAL,
        start_date="2020-09-04T12:00:00",
        end_date="2020-09-04T12:00:00",
    )
    for item in radolan.query():
        # Decode data using wradlib.
        log.info("Parsing RADOLAN_CDC composite data for %s", item.timestamp)
        data, attributes = wrl.io.read_radolan_composite(item.data)
        # Compute label matching RW/SF product.
        label = label_by_producttype(attributes["producttype"])
        # Plot and display data.
        plot(data, attributes, label)
        if "PYTEST_CURRENT_TEST" not in os.environ:
            plt.show()