def METHOD_NAME(owner, date, content):
    """
    Generate an unique Atom id for the given content
    """
    h = hashlib.sha256()
    # Hash still contains the original project url, keep as is
    h.update("github.com/spacetelescope/asv".encode('utf-8'))
    for x in content:
        if x is None:
            h.update(",".encode('utf-8'))
        else:
            h.update(x.encode('utf-8'))
        h.update(",".encode('utf-8'))
    if date is None:
        date = datetime.datetime(1970, 1, 1)
    return f"tag:{owner},{date.strftime('%Y-%m-%d')}:/{h.hexdigest()}"