def exists_s3_object(bucket, url):
    """Uses a valid S3 bucket to check the existence of a remote file as AWS URL.

    Parameters
    ----------
    bucket : S3 bucket
        Must have been created similar to
        ``boto3.session.Session().resource('s3').Bucket(BUCKET_NAME)``

    url : str
        The remote URL of the object to be fetched

    Returns
    -------
    bool
    """

    # Retrieve a collection of S3 objects with that prefix and check if non-empty
    return len(list(bucket.objects.filter(Prefix=url))) != 0