def METHOD_NAME(json_data, logger: Logger):
    """
    Identifies any unknown fuel types and logs a warning.
    Returns a tuple containing datetime object and production dictionary.
    """
    generation = json_data["Fuel"]["Type"]
    production = {}
    for fuel in generation:
        try:
            k = mapping[fuel["CATEGORY"]]
        except KeyError as e:
            logger.warning(
                "Key '{}' is missing from the MISO fuel mapping.".format(
                    fuel["CATEGORY"]
                )
            )
            k = "unknown"
        v = float(fuel["ACT"])
        production[k] = production.get(k, 0.0) + v
    # Remove unneeded parts of timestamp to allow datetime parsing.
    timestamp = json_data["RefId"]
    split_time = timestamp.split(" ")
    time_junk = {1, 2}  # set literal
    useful_time_parts = [v for i, v in enumerate(split_time) if i not in time_junk]
    if useful_time_parts[-1] != "EST":
        raise ValueError("Timezone reported for US-MISO has changed.")
    time_data = " ".join(useful_time_parts)
    tzinfos = {"EST": tz.gettz("America/New_York")}
    dt = parser.parse(time_data, tzinfos=tzinfos)
    return dt, production