def upload(to_upload):
    filename = '/tmp/what_the_duck'
    S = shelve.open(filename)
    try:
#         logger.debug('New records: %s  previous: %s' % (len(to_upload), len(S)))
        
        for u in to_upload:
            S[u['_id']] = u
        
        if not is_internet_connected():
            msg = 'Internet is not connected: cannot upload results.'
            logger.warning(msg)
        else:
            remaining = []
            for k in S:
                remaining.append(S[k])
                
            collection = get_upload_collection()
            logger.info('Uploading %s test results' % len(remaining))
            collection.insert_many(remaining)
            logger.info('done')
            for r in remaining:
                del S[r['_id']]
    finally:
#         logger.info('Remaining %s' % (len(S)))
        S.close()