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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 _track_from_response(result, timeout):
 """ This is the function that actually creates the track object """

    response = result['response']
    status = response['track']['status'].lower()

    if status == 'pending':
        # Need to wait for async upload or analyze call to finish.
        result = _wait_for_pending_track(response['track']['id'], timeout)
        response = result['response']
        status = response['track']['status'].lower()

    if not status == 'complete':
        track_id = response['track']['id']
        if status == 'pending':
            raise Exception('%s: the operation didn\'t complete before the timeout (%d secs)' %
                            (track_id, timeout))
        else:
            raise Exception('%s: there was an error analyzing the track, status: %s' % (track_id, status))
    else:
        # track_properties starts as the response dictionary.
        track_properties = response['track']
        # 'id' and 'md5' are separated to construct the Track object.
        identifier = track_properties.pop('id')
        md5        = track_properties.pop('md5', None) # tracks from song api calls will not have an md5
        # Pop off the audio_summary dict and make those keys attributes
        # of the Track. This includes things like tempo, energy, and loudness.
        track_properties.update(track_properties.pop('audio_summary'))
        return Track(identifier, md5, track_properties)