def METHOD_NAME(cls, prefix):
    """Helper to generate custom datalad URL prefixes
    """
    # prefix which will be used in all URLs supported by this custom remote
    # https://tools.ietf.org/html/rfc2718 dictates "URL Schemes" standard
    # 2.1.2 suggests that we do use // since all of our URLs will define
    # some hierarchical structure.  But actually since we might encode
    # additional information (such as size) into the URL, it will not be
    # strictly conforming it. Thus we will not use //
    return "%s+%s" % (URI_PREFIX, prefix)  # if .PREFIX else '')