def list_objects(s3, bucket, token=None):
    """
        list objects on Amazon S3. 
        Return a continuation token (pagination) and the response body.

        Parameters
        ----------
        s3 : 
            the session token authorization for the S3 Client
        bucket : 
            the bucket name passed as an CLI argument
        token : string
            the continuation token, if it exists

        Returns
        -------
        response : dict
            the response body of the list_objects_v2 API
        token : string
            a pagination (continuation) token to get the next set of objects
    """
    response = s3.list_objects_v2(
        Bucket=bucket
    )

    if (response['IsTruncated'] != False):
        token = response['NextContinuationToken']
    else:
        token = None
 
    return response, token