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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 antennas_missing_locations(user, Method=None):
 """ Return the number of antennas missing locations in the records of a given user. """

    unique_antennas = set([record.position.antenna for record in user.records
                           if record.position.antenna is not None])
    return sum([1 for antenna in unique_antennas if user.antennas.get(antenna) is None])