def get_s3_prefixes(collection):
    """ Returns array of S3 prefixes for given collection """
    if 'DirectDistributionInformation' in collection:
        direct_dist = collection['DirectDistributionInformation']
        if 'S3BucketAndObjectPrefixNames' in direct_dist:
            return direct_dist['S3BucketAndObjectPrefixNames']
    return []