Return a list of the fields we need to map a sponser to a bill

def extract_sponsor(bill):
    """
    Return a list of the fields we need to map a sponser to a bill
    """
    logger.debug("Extracting Sponsor")
    sponsor_map = []
    sponsor = bill.get('sponsor', None)
    if sponsor:
        sponsor_map.append(sponsor.get('type'))
        sponsor_map.append(sponsor.get('thomas_id'))
        sponsor_map.append(bill.get('bill_id'))
        sponsor_map.append(sponsor.get('district'))
        sponsor_map.append(sponsor.get('state'))
    logger.debug("END Extracting Sponsor")
    return sponsor_map if sponsor_map else None