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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def query_icao(icao: str):
 """ Queries AWC for the METAR of a given station Args: icao: station ID as a four letters-digits ICAO code Returns: AWC result for the station """

        params = {
            'dataSource': 'metars',
            'requestType': 'retrieve',
            'format': 'csv',
            'hoursBeforeNow': 24,
        }
        AWC._validate_icao(icao)
        params['stationString'] = icao
        try:
            return AWC._query(params)
        except RequestsConnectionError:
            raise AWCRequestFailed('failed to obtain requested data from AWC')